Merge branch 'V2' into auto-rename

frontend/eslint.config.mjs

@@ -15,11 +15,14 @@ export default defineConfig(
   },
   {
     rules: {
-      "no-empty-pattern": "off", // Temporarily disabled until codebase conformant
       "no-undef": "off", // Temporarily disabled until codebase conformant
-      "no-case-declarations": "off", // Temporarily disabled until codebase conformant
+      "@typescript-eslint/no-empty-object-type": [
-      "@typescript-eslint/ban-ts-comment": "off", // Temporarily disabled until codebase conformant
+        "error",
-      "@typescript-eslint/no-empty-object-type": "off", // Temporarily disabled until codebase conformant
+        {
+          // Allow empty extending interfaces because there's no real reason not to, and it makes it obvious where to put extra attributes in the future
+          allowInterfaces: 'with-single-extends',
+        },
+      ],
       "@typescript-eslint/no-explicit-any": "off", // Temporarily disabled until codebase conformant
       "@typescript-eslint/no-require-imports": "off", // Temporarily disabled until codebase conformant
       "@typescript-eslint/no-unused-vars": "off", // Temporarily disabled until codebase conformant

frontend/src/App.tsx

@@ -14,6 +14,9 @@ import "./styles/cookieconsent.css";
 import "./index.css";
 import { RightRailProvider } from "./contexts/RightRailContext";
 
+// Import file ID debugging helpers (development only)
+import "./utils/fileIdSafety";
+
 // Loading component for i18next suspense
 const LoadingFallback = () => (
   <div

frontend/src/components/FileManager.tsx

@@ -24,7 +24,7 @@ const FileManager: React.FC<FileManagerProps> = ({ selectedTool }) => {
   const { loadRecentFiles, handleRemoveFile, storeFile, convertToFile } = useFileManager();
 
   // Wrapper for storeFile that generates UUID
-  const storeFileWithId = useCallback(async (file: File) => {
+  const storeStirlingFile = useCallback(async (file: File) => {
     const fileId = createFileId(); // Generate UUID for storage
     return await storeFile(file, fileId);
   }, [storeFile]);

frontend/src/components/fileEditor/FileEditor.tsx

@@ -16,12 +16,12 @@ import styles from './FileEditor.module.css';
 import FileEditorThumbnail from './FileEditorThumbnail';
 import FilePickerModal from '../shared/FilePickerModal';
 import SkeletonLoader from '../shared/SkeletonLoader';
-import { FileId } from '../../types/file';
+import { FileId, StirlingFile } from '../../types/fileContext';
 
 
 interface FileEditorProps {
-  onOpenPageEditor?: (file: File) => void;
+  onOpenPageEditor?: (file: StirlingFile) => void;
-  onMergeFiles?: (files: File[]) => void;
+  onMergeFiles?: (files: StirlingFile[]) => void;
   toolMode?: boolean;
   showUpload?: boolean;
   showBulkActions?: boolean;
@@ -50,7 +50,7 @@ const FileEditor = ({
 
   // Extract needed values from state (memoized to prevent infinite loops)
   const activeFiles = useMemo(() => selectors.getFiles(), [selectors.getFilesSignature()]);
-  const activeFileRecords = useMemo(() => selectors.getFileRecords(), [selectors.getFilesSignature()]);
+  const activeStirlingFileStubs = useMemo(() => selectors.getStirlingFileStubs(), [selectors.getFilesSignature()]);
   const selectedFileIds = state.ui.selectedFileIds;
   const isProcessing = state.ui.isProcessing;
 
@@ -92,10 +92,10 @@ const FileEditor = ({
   const contextSelectedIdsRef = useRef<FileId[]>([]);
   contextSelectedIdsRef.current = contextSelectedIds;
 
-  // Use activeFileRecords directly - no conversion needed
+  // Use activeStirlingFileStubs directly - no conversion needed
   const localSelectedIds = contextSelectedIds;
 
-  // Helper to convert FileRecord to FileThumbnail format
+  // Helper to convert StirlingFileStub to FileThumbnail format
   const recordToFileItem = useCallback((record: any) => {
     const file = selectors.getFile(record.id);
     if (!file) return null;
@@ -253,26 +253,26 @@ const FileEditor = ({
   }, [addFiles]);
 
   const selectAll = useCallback(() => {
-    setSelectedFiles(activeFileRecords.map(r => r.id)); // Use FileRecord IDs directly
+    setSelectedFiles(activeStirlingFileStubs.map(r => r.id)); // Use StirlingFileStub IDs directly
-  }, [activeFileRecords, setSelectedFiles]);
+  }, [activeStirlingFileStubs, setSelectedFiles]);
 
   const deselectAll = useCallback(() => setSelectedFiles([]), [setSelectedFiles]);
 
   const closeAllFiles = useCallback(() => {
-    if (activeFileRecords.length === 0) return;
+    if (activeStirlingFileStubs.length === 0) return;
 
     // Remove all files from context but keep in storage
-    const allFileIds = activeFileRecords.map(record => record.id);
+    const allFileIds = activeStirlingFileStubs.map(record => record.id);
     removeFiles(allFileIds, false); // false = keep in storage
 
     // Clear selections
     setSelectedFiles([]);
-  }, [activeFileRecords, removeFiles, setSelectedFiles]);
+  }, [activeStirlingFileStubs, removeFiles, setSelectedFiles]);
 
   const toggleFile = useCallback((fileId: FileId) => {
     const currentSelectedIds = contextSelectedIdsRef.current;
 
-    const targetRecord = activeFileRecords.find(r => r.id === fileId);
+    const targetRecord = activeStirlingFileStubs.find(r => r.id === fileId);
     if (!targetRecord) return;
 
     const contextFileId = fileId; // No need to create a new ID
@@ -302,7 +302,7 @@ const FileEditor = ({
 
     // Update context (this automatically updates tool selection since they use the same action)
     setSelectedFiles(newSelection);
-  }, [setSelectedFiles, toolMode, setStatus, activeFileRecords]);
+  }, [setSelectedFiles, toolMode, setStatus, activeStirlingFileStubs]);
 
   const toggleSelectionMode = useCallback(() => {
     setSelectionMode(prev => {
@@ -316,7 +316,7 @@ const FileEditor = ({
 
   // File reordering handler for drag and drop
   const handleReorderFiles = useCallback((sourceFileId: FileId, targetFileId: FileId, selectedFileIds: FileId[]) => {
-    const currentIds = activeFileRecords.map(r => r.id);
+    const currentIds = activeStirlingFileStubs.map(r => r.id);
 
     // Find indices
     const sourceIndex = currentIds.findIndex(id => id === sourceFileId);
@@ -368,13 +368,13 @@ const FileEditor = ({
     // Update status
     const moveCount = filesToMove.length;
     setStatus(`${moveCount > 1 ? `${moveCount} files` : 'File'} reordered`);
-  }, [activeFileRecords, reorderFiles, setStatus]);
+  }, [activeStirlingFileStubs, reorderFiles, setStatus]);
 
 
 
   // File operations using context
   const handleDeleteFile = useCallback((fileId: FileId) => {
-    const record = activeFileRecords.find(r => r.id === fileId);
+    const record = activeStirlingFileStubs.find(r => r.id === fileId);
     const file = record ? selectors.getFile(record.id) : null;
 
     if (record && file) {
@@ -405,27 +405,27 @@ const FileEditor = ({
       const currentSelected = selectedFileIds.filter(id => id !== contextFileId);
       setSelectedFiles(currentSelected);
     }
-  }, [activeFileRecords, selectors, removeFiles, setSelectedFiles, selectedFileIds]);
+  }, [activeStirlingFileStubs, selectors, removeFiles, setSelectedFiles, selectedFileIds]);
 
   const handleViewFile = useCallback((fileId: FileId) => {
-    const record = activeFileRecords.find(r => r.id === fileId);
+    const record = activeStirlingFileStubs.find(r => r.id === fileId);
     if (record) {
       // Set the file as selected in context and switch to viewer for preview
       setSelectedFiles([fileId]);
       navActions.setWorkbench('viewer');
     }
-  }, [activeFileRecords, setSelectedFiles, navActions.setWorkbench]);
+  }, [activeStirlingFileStubs, setSelectedFiles, navActions.setWorkbench]);
 
   const handleMergeFromHere = useCallback((fileId: FileId) => {
-    const startIndex = activeFileRecords.findIndex(r => r.id === fileId);
+    const startIndex = activeStirlingFileStubs.findIndex(r => r.id === fileId);
     if (startIndex === -1) return;
 
-    const recordsToMerge = activeFileRecords.slice(startIndex);
+    const recordsToMerge = activeStirlingFileStubs.slice(startIndex);
-    const filesToMerge = recordsToMerge.map(r => selectors.getFile(r.id)).filter(Boolean) as File[];
+    const filesToMerge = recordsToMerge.map(r => selectors.getFile(r.id)).filter(Boolean) as StirlingFile[];
     if (onMergeFiles) {
       onMergeFiles(filesToMerge);
     }
-  }, [activeFileRecords, selectors, onMergeFiles]);
+  }, [activeStirlingFileStubs, selectors, onMergeFiles]);
 
   const handleSplitFile = useCallback((fileId: FileId) => {
     const file = selectors.getFile(fileId);
@@ -467,7 +467,7 @@ const FileEditor = ({
         <Box p="md" pt="xl">
 
 
-        {activeFileRecords.length === 0 && !zipExtractionProgress.isExtracting ? (
+        {activeStirlingFileStubs.length === 0 && !zipExtractionProgress.isExtracting ? (
           <Center h="60vh">
             <Stack align="center" gap="md">
               <Text size="lg" c="dimmed">📁</Text>
@@ -475,7 +475,7 @@ const FileEditor = ({
               <Text size="sm" c="dimmed">Upload PDF files, ZIP archives, or load from storage to get started</Text>
             </Stack>
           </Center>
-        ) : activeFileRecords.length === 0 && zipExtractionProgress.isExtracting ? (
+        ) : activeStirlingFileStubs.length === 0 && zipExtractionProgress.isExtracting ? (
           <Box>
             <SkeletonLoader type="controls" />
 
@@ -522,7 +522,7 @@ const FileEditor = ({
               pointerEvents: 'auto'
             }}
           >
-            {activeFileRecords.map((record, index) => {
+            {activeStirlingFileStubs.map((record, index) => {
               const fileItem = recordToFileItem(record);
               if (!fileItem) return null;
 
@@ -531,7 +531,7 @@ const FileEditor = ({
                   key={record.id}
                   file={fileItem}
                   index={index}
-                  totalFiles={activeFileRecords.length}
+                  totalFiles={activeStirlingFileStubs.length}
                   selectedFiles={localSelectedIds}
                   selectionMode={selectionMode}
                   onToggleFile={toggleFile}

frontend/src/components/fileEditor/FileEditorThumbnail.tsx

@@ -61,8 +61,8 @@ const FileEditorThumbnail = ({
 
   // Resolve the actual File object for pin/unpin operations
   const actualFile = useMemo(() => {
-    return activeFiles.find((f: File) => f.name === file.name && f.size === file.size);
+    return activeFiles.find(f => f.fileId === file.id);
-  }, [activeFiles, file.name, file.size]);
+  }, [activeFiles, file.id]);
   const isPinned = actualFile ? isFilePinned(actualFile) : false;
 
   const downloadSelectedFile = useCallback(() => {

frontend/src/components/pageEditor/FileThumbnail.tsx

@@ -61,8 +61,8 @@ const FileThumbnail = ({
 
   // Resolve the actual File object for pin/unpin operations
   const actualFile = useMemo(() => {
-    return activeFiles.find((f: File) => f.name === file.name && f.size === file.size);
+    return activeFiles.find(f => f.fileId === file.id);
-  }, [activeFiles, file.name, file.size]);
+  }, [activeFiles, file.id]);
   const isPinned = actualFile ? isFilePinned(actualFile) : false;
 
   const downloadSelectedFile = useCallback(() => {

frontend/src/components/pageEditor/hooks/usePageDocument.ts

@@ -27,9 +27,9 @@ export function usePageDocument(): PageDocumentHook {
   const globalProcessing = state.ui.isProcessing;
 
   // Get primary file record outside useMemo to track processedFile changes
-  const primaryFileRecord = primaryFileId ? selectors.getFileRecord(primaryFileId) : null;
+  const primaryStirlingFileStub = primaryFileId ? selectors.getStirlingFileStub(primaryFileId) : null;
-  const processedFilePages = primaryFileRecord?.processedFile?.pages;
+  const processedFilePages = primaryStirlingFileStub?.processedFile?.pages;
-  const processedFileTotalPages = primaryFileRecord?.processedFile?.totalPages;
+  const processedFileTotalPages = primaryStirlingFileStub?.processedFile?.totalPages;
 
   // Compute merged document with stable signature (prevents infinite loops)
   const mergedPdfDocument = useMemo((): PDFDocument | null => {
@@ -38,16 +38,16 @@ export function usePageDocument(): PageDocumentHook {
     const primaryFile = primaryFileId ? selectors.getFile(primaryFileId) : null;
 
     // If we have file IDs but no file record, something is wrong - return null to show loading
-    if (!primaryFileRecord) {
+    if (!primaryStirlingFileStub) {
       console.log('🎬 PageEditor: No primary file record found, showing loading');
       return null;
     }
 
     const name =
       activeFileIds.length === 1
-        ? (primaryFileRecord.name ?? 'document.pdf')
+        ? (primaryStirlingFileStub.name ?? 'document.pdf')
         : activeFileIds
-            .map(id => (selectors.getFileRecord(id)?.name ?? 'file').replace(/\.pdf$/i, ''))
+            .map(id => (selectors.getStirlingFileStub(id)?.name ?? 'file').replace(/\.pdf$/i, ''))
             .join(' + ');
 
     // Build page insertion map from files with insertion positions
@@ -55,7 +55,7 @@ export function usePageDocument(): PageDocumentHook {
     const originalFileIds: FileId[] = [];
 
     activeFileIds.forEach(fileId => {
-      const record = selectors.getFileRecord(fileId);
+      const record = selectors.getStirlingFileStub(fileId);
       if (record?.insertAfterPageId !== undefined) {
         if (!insertionMap.has(record.insertAfterPageId)) {
           insertionMap.set(record.insertAfterPageId, []);
@@ -72,12 +72,12 @@ export function usePageDocument(): PageDocumentHook {
 
     // Helper function to create pages from a file
     const createPagesFromFile = (fileId: FileId, startPageNumber: number): PDFPage[] => {
-      const fileRecord = selectors.getFileRecord(fileId);
+      const stirlingFileStub = selectors.getStirlingFileStub(fileId);
-      if (!fileRecord) {
+      if (!stirlingFileStub) {
         return [];
       }
 
-      const processedFile = fileRecord.processedFile;
+      const processedFile = stirlingFileStub.processedFile;
       let filePages: PDFPage[] = [];
 
       if (processedFile?.pages && processedFile.pages.length > 0) {
@@ -159,7 +159,7 @@ export function usePageDocument(): PageDocumentHook {
     };
 
     return mergedDoc;
-  }, [activeFileIds, primaryFileId, primaryFileRecord, processedFilePages, processedFileTotalPages, selectors, filesSignature]);
+  }, [activeFileIds, primaryFileId, primaryStirlingFileStub, processedFilePages, processedFileTotalPages, selectors, filesSignature]);
 
   // Large document detection for smart loading
   const isVeryLargeDocument = useMemo(() => {

frontend/src/components/shared/FileCard.tsx

@@ -6,13 +6,13 @@ import StorageIcon from "@mui/icons-material/Storage";
 import VisibilityIcon from "@mui/icons-material/Visibility";
 import EditIcon from "@mui/icons-material/Edit";
 
-import { FileRecord } from "../../types/fileContext";
+import { StirlingFileStub } from "../../types/fileContext";
 import { getFileSize, getFileDate } from "../../utils/fileUtils";
 import { useIndexedDBThumbnail } from "../../hooks/useIndexedDBThumbnail";
 
 interface FileCardProps {
   file: File;
-  record?: FileRecord;
+  record?: StirlingFileStub;
   onRemove: () => void;
   onDoubleClick?: () => void;
   onView?: () => void;
@@ -25,7 +25,7 @@ interface FileCardProps {
 const FileCard = ({ file, record, onRemove, onDoubleClick, onView, onEdit, isSelected, onSelect, isSupported = true }: FileCardProps) => {
   const { t } = useTranslation();
   // Use record thumbnail if available, otherwise fall back to IndexedDB lookup
-  const fileMetadata = record ? { id: record.id, name: file.name, type: file.type, size: file.size, lastModified: file.lastModified } : null;
+  const fileMetadata = record ? { id: record.id, name: record.name, type: record.type, size: record.size, lastModified: record.lastModified } : null;
   const { thumbnail: indexedDBThumb, isGenerating } = useIndexedDBThumbnail(fileMetadata);
   const thumb = record?.thumbnailUrl || indexedDBThumb;
   const [isHovered, setIsHovered] = useState(false);

frontend/src/components/shared/FileGrid.tsx

@@ -4,15 +4,15 @@ import { useTranslation } from "react-i18next";
 import SearchIcon from "@mui/icons-material/Search";
 import SortIcon from "@mui/icons-material/Sort";
 import FileCard from "./FileCard";
-import { FileRecord } from "../../types/fileContext";
+import { StirlingFileStub } from "../../types/fileContext";
 import { FileId } from "../../types/file";
 
 interface FileGridProps {
-  files: Array<{ file: File; record?: FileRecord }>;
+  files: Array<{ file: File; record?: StirlingFileStub }>;
   onRemove?: (index: number) => void;
-  onDoubleClick?: (item: { file: File; record?: FileRecord }) => void;
+  onDoubleClick?: (item: { file: File; record?: StirlingFileStub }) => void;
-  onView?: (item: { file: File; record?: FileRecord }) => void;
+  onView?: (item: { file: File; record?: StirlingFileStub }) => void;
-  onEdit?: (item: { file: File; record?: FileRecord }) => void;
+  onEdit?: (item: { file: File; record?: StirlingFileStub }) => void;
   onSelect?: (fileId: FileId) => void;
   selectedFiles?: FileId[];
   showSearch?: boolean;
@@ -123,9 +123,17 @@ const FileGrid = ({
         h="30rem"
         style={{ overflowY: "auto", width: "100%" }}
       >
-        {displayFiles.map((item, idx) => {
+        {displayFiles
-          const fileId = item.record?.id || item.file.name as FileId /* FIX ME: This doesn't seem right */;
+          .filter(item => {
-          const originalIdx = files.findIndex(f => (f.record?.id || f.file.name) === fileId);
+            if (!item.record?.id) {
+              console.error('FileGrid: File missing StirlingFileStub with proper ID:', item.file.name);
+              return false;
+            }
+            return true;
+          })
+          .map((item, idx) => {
+          const fileId = item.record!.id; // Safe to assert after filter
+          const originalIdx = files.findIndex(f => f.record?.id === fileId);
           const supported = isFileSupported ? isFileSupported(item.file.name) : true;
           return (
             <FileCard

frontend/src/components/shared/QuickAccessBar.tsx

@@ -17,8 +17,7 @@ import {
   getActiveNavButton,
 } from './quickAccessBar/QuickAccessBar';
 
-const QuickAccessBar = forwardRef<HTMLDivElement>(({
+const QuickAccessBar = forwardRef<HTMLDivElement>((_, ref) => {
-}, ref) => {
   const { t } = useTranslation();
   const { isRainbowMode } = useRainbowThemeContext();
   const { openFilesModal, isFilesModalOpen } = useFilesModalContext();

frontend/src/components/shared/RightRail.tsx

@@ -34,7 +34,6 @@ export default function RightRail() {
 
   const activeFiles = selectors.getFiles();
   const filesSignature = selectors.getFilesSignature();
-  const fileRecords = selectors.getFileRecords();
 
   // Compute selection state and total items
   const getSelectionState = useCallback(() => {
@@ -85,7 +84,7 @@ export default function RightRail() {
     if (currentView === 'fileEditor' || currentView === 'viewer') {
       // Download selected files (or all if none selected)
       const filesToDownload = selectedFiles.length > 0 ? selectedFiles : activeFiles;
-      
+
       filesToDownload.forEach(file => {
         const link = document.createElement('a');
         link.href = URL.createObjectURL(file);
@@ -206,8 +205,8 @@ export default function RightRail() {
         )}
 
         {/* Group: Selection controls + Close, animate as one unit when entering/leaving viewer */}
-        <div 
+        <div
-          className={`right-rail-slot ${currentView !== 'viewer' ? 'visible right-rail-enter' : 'right-rail-exit'}`} 
+          className={`right-rail-slot ${currentView !== 'viewer' ? 'visible right-rail-enter' : 'right-rail-exit'}`}
           aria-hidden={currentView === 'viewer'}
         >
           <div style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: '1rem' }}>
@@ -358,14 +357,14 @@ export default function RightRail() {
           <LanguageSelector position="left-start" offset={6} compact />
 
           <Tooltip content={
-            currentView === 'pageEditor' 
+            currentView === 'pageEditor'
-              ? t('rightRail.exportAll', 'Export PDF') 
+              ? t('rightRail.exportAll', 'Export PDF')
               : (selectedCount > 0 ? t('rightRail.downloadSelected', 'Download Selected Files') : t('rightRail.downloadAll', 'Download All'))
           } position="left" offset={12} arrow>
             <div>
-              <ActionIcon 
+              <ActionIcon
-                variant="subtle" 
+                variant="subtle"
-                radius="md" 
+                radius="md"
                 className="right-rail-icon"
                 onClick={handleExportAll}
                 disabled={currentView === 'viewer' || totalItems === 0}

frontend/src/components/tools/convert/ConvertSettings.tsx

@@ -22,13 +22,13 @@ import {
   OUTPUT_OPTIONS,
   FIT_OPTIONS
 } from "../../../constants/convertConstants";
-import { FileId } from "../../../types/file";
+import { StirlingFile } from "../../../types/fileContext";
 
 interface ConvertSettingsProps {
   parameters: ConvertParameters;
   onParameterChange: (key: keyof ConvertParameters, value: any) => void;
   getAvailableToExtensions: (fromExtension: string) => Array<{value: string, label: string, group: string}>;
-  selectedFiles: File[];
+  selectedFiles: StirlingFile[];
   disabled?: boolean;
 }
 
@@ -129,7 +129,7 @@ const ConvertSettings = ({
   };
 
   const filterFilesByExtension = (extension: string) => {
-    const files = activeFiles.map(fileId => selectors.getFile(fileId)).filter(Boolean) as File[];
+    const files = activeFiles.map(fileId => selectors.getFile(fileId)).filter(Boolean) as StirlingFile[];
     return files.filter(file => {
       const fileExtension = detectFileExtension(file.name);
 
@@ -143,21 +143,8 @@ const ConvertSettings = ({
     });
   };
 
-  const updateFileSelection = (files: File[]) => {
+  const updateFileSelection = (files: StirlingFile[]) => {
-    // Map File objects to their actual IDs in FileContext
+    const fileIds = files.map(file => file.fileId);
-    const fileIds = files.map(file => {
-      // Find the file ID by matching file properties
-      const fileRecord = state.files.ids
-        .map(id => selectors.getFileRecord(id))
-        .find(record =>
-          record &&
-          record.name === file.name &&
-          record.size === file.size &&
-          record.lastModified === file.lastModified
-        );
-      return fileRecord?.id;
-    }).filter((id): id is FileId => id !== undefined); // Type guard to ensure only strings
-
     setSelectedFiles(fileIds);
   };
 

frontend/src/components/tools/convert/ConvertToPdfaSettings.tsx

@@ -3,11 +3,12 @@ import { Stack, Text, Select, Alert } from '@mantine/core';
 import { useTranslation } from 'react-i18next';
 import { ConvertParameters } from '../../../hooks/tools/convert/useConvertParameters';
 import { usePdfSignatureDetection } from '../../../hooks/usePdfSignatureDetection';
+import { StirlingFile } from '../../../types/fileContext';
 
 interface ConvertToPdfaSettingsProps {
   parameters: ConvertParameters;
   onParameterChange: (key: keyof ConvertParameters, value: any) => void;
-  selectedFiles: File[];
+  selectedFiles: StirlingFile[];
   disabled?: boolean;
 }
 

frontend/src/components/tools/shared/FileStatusIndicator.tsx

@@ -6,9 +6,10 @@ import UploadIcon from '@mui/icons-material/Upload';
 import { useFilesModalContext } from "../../../contexts/FilesModalContext";
 import { useAllFiles } from "../../../contexts/FileContext";
 import { useFileManager } from "../../../hooks/useFileManager";
+import { StirlingFile } from "../../../types/fileContext";
 
 export interface FileStatusIndicatorProps {
-  selectedFiles?: File[];
+  selectedFiles?: StirlingFile[];
   placeholder?: string;
 }
 
@@ -17,7 +18,7 @@ const FileStatusIndicator = ({
 }: FileStatusIndicatorProps) => {
   const { t } = useTranslation();
   const { openFilesModal, onFilesSelect } = useFilesModalContext();
-  const { files: workbenchFiles } = useAllFiles();
+  const { files: stirlingFileStubs } = useAllFiles();
   const { loadRecentFiles } = useFileManager();
   const [hasRecentFiles, setHasRecentFiles] = useState<boolean | null>(null);
 
@@ -55,7 +56,7 @@ const FileStatusIndicator = ({
   }
 
   // Check if there are no files in the workbench
-  if (workbenchFiles.length === 0) {
+  if (stirlingFileStubs.length === 0) {
     // If no recent files, show upload button
     if (!hasRecentFiles) {
       return (

frontend/src/components/tools/shared/FilesToolStep.tsx

@@ -1,9 +1,10 @@
 import React from 'react';
 import { useTranslation } from 'react-i18next';
 import FileStatusIndicator from './FileStatusIndicator';
+import { StirlingFile } from '../../../types/fileContext';
 
 export interface FilesToolStepProps {
-  selectedFiles: File[];
+  selectedFiles: StirlingFile[];
   isCollapsed?: boolean;
   onCollapsedClick?: () => void;
   placeholder?: string;

frontend/src/components/tools/shared/SuggestedToolsSection.tsx

@@ -3,8 +3,6 @@ import { Stack, Text, Divider, Card, Group } from '@mantine/core';
 import { useTranslation } from 'react-i18next';
 import { useSuggestedTools } from '../../../hooks/useSuggestedTools';
 
-export interface SuggestedToolsSectionProps {}
-
 export function SuggestedToolsSection(): React.ReactElement {
   const { t } = useTranslation();
   const suggestedTools = useSuggestedTools();

frontend/src/components/tools/shared/createToolFlow.tsx

@@ -4,9 +4,10 @@ import { createToolSteps, ToolStepProvider } from './ToolStep';
 import OperationButton from './OperationButton';
 import { ToolOperationHook } from '../../../hooks/tools/shared/useToolOperation';
 import { ToolWorkflowTitle, ToolWorkflowTitleProps } from './ToolWorkflowTitle';
+import { StirlingFile } from '../../../types/fileContext';
 
 export interface FilesStepConfig {
-  selectedFiles: File[];
+  selectedFiles: StirlingFile[];
   isCollapsed?: boolean;
   placeholder?: string;
   onCollapsedClick?: () => void;

frontend/src/components/viewer/Viewer.tsx

@@ -15,6 +15,7 @@ import { fileStorage } from "../../services/fileStorage";
 import SkeletonLoader from '../shared/SkeletonLoader';
 import { useFileState, useFileActions, useCurrentFile } from "../../contexts/FileContext";
 import { useFileWithUrl } from "../../hooks/useFileWithUrl";
+import { isFileObject } from "../../types/fileContext";
 import { FileId } from "../../types/file";
 
 
@@ -201,7 +202,7 @@ const Viewer = ({
   const effectiveFile = React.useMemo(() => {
     if (previewFile) {
       // Validate the preview file
-      if (!(previewFile instanceof File)) {
+      if (!isFileObject(previewFile)) {
         return null;
       }
 

frontend/src/contexts/FileContext.tsx

@@ -19,7 +19,10 @@ import {
   FileContextStateValue,
   FileContextActionsValue,
   FileContextActions,
-  FileRecord
+  FileId,
+  StirlingFileStub,
+  StirlingFile,
+  createStirlingFile
 } from '../types/fileContext';
 
 // Import modular components
@@ -29,7 +32,6 @@ import { AddedFile, addFiles, consumeFiles, undoConsumeFiles, createFileActions
 import { FileLifecycleManager } from './file/lifecycle';
 import { FileStateContext, FileActionsContext } from './file/contexts';
 import { IndexedDBProvider, useIndexedDB } from './IndexedDBContext';
-import { FileId } from '../types/file';
 
 const DEBUG = process.env.NODE_ENV === 'development';
 
@@ -79,7 +81,7 @@ function FileContextInner({
   }
 
   // File operations using unified addFiles helper with persistence
-  const addRawFiles = useCallback(async (files: File[], options?: { insertAfterPageId?: string; selectFiles?: boolean }): Promise<File[]> => {
+  const addRawFiles = useCallback(async (files: File[], options?: { insertAfterPageId?: string; selectFiles?: boolean }): Promise<StirlingFile[]> => {
     const addedFilesWithIds = await addFiles('raw', { files, ...options }, stateRef, filesRef, dispatch, lifecycleManager);
 
     // Auto-select the newly added files if requested
@@ -98,15 +100,15 @@ function FileContextInner({
       }));
     }
 
-    return addedFilesWithIds.map(({ file }) => file);
+    return addedFilesWithIds.map(({ file, id }) => createStirlingFile(file, id));
   }, [indexedDB, enablePersistence]);
 
-  const addProcessedFiles = useCallback(async (filesWithThumbnails: Array<{ file: File; thumbnail?: string; pageCount?: number }>): Promise<File[]> => {
+  const addProcessedFiles = useCallback(async (filesWithThumbnails: Array<{ file: File; thumbnail?: string; pageCount?: number }>): Promise<StirlingFile[]> => {
     const result = await addFiles('processed', { filesWithThumbnails }, stateRef, filesRef, dispatch, lifecycleManager);
-    return result.map(({ file }) => file);
+    return result.map(({ file, id }) => createStirlingFile(file, id));
   }, []);
 
-  const addStoredFiles = useCallback(async (filesWithMetadata: Array<{ file: File; originalId: FileId; metadata: any }>, options?: { selectFiles?: boolean }): Promise<File[]> => {
+  const addStoredFiles = useCallback(async (filesWithMetadata: Array<{ file: File; originalId: FileId; metadata: any }>, options?: { selectFiles?: boolean }): Promise<StirlingFile[]> => {
     const result = await addFiles('stored', { filesWithMetadata }, stateRef, filesRef, dispatch, lifecycleManager);
 
     // Auto-select the newly added files if requested
@@ -114,7 +116,7 @@ function FileContextInner({
       selectFiles(result);
     }
 
-    return result.map(({ file }) => file);
+    return result.map(({ file, id }) => createStirlingFile(file, id));
   }, []);
 
   // Action creators
@@ -122,11 +124,11 @@ function FileContextInner({
 
   // Helper functions for pinned files
   const consumeFilesWrapper = useCallback(async (inputFileIds: FileId[], outputFiles: File[]): Promise<FileId[]> => {
-    return consumeFiles(inputFileIds, outputFiles, stateRef, filesRef, dispatch, indexedDB);
+    return consumeFiles(inputFileIds, outputFiles, filesRef, dispatch, indexedDB);
   }, [indexedDB]);
 
-  const undoConsumeFilesWrapper = useCallback(async (inputFiles: File[], inputFileRecords: FileRecord[], outputFileIds: FileId[]): Promise<void> => {
+  const undoConsumeFilesWrapper = useCallback(async (inputFiles: File[], inputStirlingFileStubs: StirlingFileStub[], outputFileIds: FileId[]): Promise<void> => {
-    return undoConsumeFiles(inputFiles, inputFileRecords, outputFileIds, stateRef, filesRef, dispatch, indexedDB);
+    return undoConsumeFiles(inputFiles, inputStirlingFileStubs, outputFileIds, stateRef, filesRef, dispatch, indexedDB);
   }, [indexedDB]);
 
   // Helper to find FileId from File object
@@ -140,24 +142,14 @@ function FileContextInner({
     });
   }, []);
 
-  // File-to-ID wrapper functions for pinning
+  // File pinning functions - use StirlingFile directly
-  const pinFileWrapper = useCallback((file: File) => {
+  const pinFileWrapper = useCallback((file: StirlingFile) => {
-    const fileId = findFileId(file);
+    baseActions.pinFile(file.fileId);
-    if (fileId) {
+  }, [baseActions]);
-      baseActions.pinFile(fileId);
-    } else {
-      console.warn('File not found for pinning:', file.name);
-    }
-  }, [baseActions, findFileId]);
 
-  const unpinFileWrapper = useCallback((file: File) => {
+  const unpinFileWrapper = useCallback((file: StirlingFile) => {
-    const fileId = findFileId(file);
+    baseActions.unpinFile(file.fileId);
-    if (fileId) {
+  }, [baseActions]);
-      baseActions.unpinFile(fileId);
-    } else {
-      console.warn('File not found for unpinning:', file.name);
-    }
-  }, [baseActions, findFileId]);
 
   // Complete actions object
   const actions = useMemo<FileContextActions>(() => ({
@@ -178,8 +170,8 @@ function FileContextInner({
         }
       }
     },
-    updateFileRecord: (fileId: FileId, updates: Partial<FileRecord>) =>
+    updateStirlingFileStub: (fileId: FileId, updates: Partial<StirlingFileStub>) =>
-      lifecycleManager.updateFileRecord(fileId, updates, stateRef),
+      lifecycleManager.updateStirlingFileStub(fileId, updates, stateRef),
     reorderFiles: (orderedFileIds: FileId[]) => {
       dispatch({ type: 'REORDER_FILES', payload: { orderedFileIds } });
     },
@@ -303,7 +295,7 @@ export {
   useFileSelection,
   useFileManagement,
   useFileUI,
-  useFileRecord,
+  useStirlingFileStub,
   useAllFiles,
   useSelectedFiles,
   // Primary API hooks for tools

frontend/src/contexts/file/FileReducer.ts

@@ -6,7 +6,7 @@ import { FileId } from '../../types/file';
 import {
   FileContextState,
   FileContextAction,
-  FileRecord
+  StirlingFileStub
 } from '../../types/fileContext';
 
 // Initial state
@@ -29,7 +29,7 @@ export const initialFileContextState: FileContextState = {
 function processFileSwap(
   state: FileContextState,
   filesToRemove: FileId[],
-  filesToAdd: FileRecord[]
+  filesToAdd: StirlingFileStub[]
 ): FileContextState {
   // Only remove unpinned files
   const unpinnedRemoveIds = filesToRemove.filter(id => !state.pinnedFiles.has(id));
@@ -70,11 +70,11 @@ function processFileSwap(
 export function fileContextReducer(state: FileContextState, action: FileContextAction): FileContextState {
   switch (action.type) {
     case 'ADD_FILES': {
-      const { fileRecords } = action.payload;
+      const { stirlingFileStubs } = action.payload;
       const newIds: FileId[] = [];
-      const newById: Record<FileId, FileRecord> = { ...state.files.byId };
+      const newById: Record<FileId, StirlingFileStub> = { ...state.files.byId };
 
-      fileRecords.forEach(record => {
+      stirlingFileStubs.forEach(record => {
         // Only add if not already present (dedupe by stable ID)
         if (!newById[record.id]) {
           newIds.push(record.id);
@@ -233,13 +233,13 @@ export function fileContextReducer(state: FileContextState, action: FileContextA
     }
 
     case 'CONSUME_FILES': {
-      const { inputFileIds, outputFileRecords } = action.payload;
+      const { inputFileIds, outputStirlingFileStubs } = action.payload;
-      return processFileSwap(state, inputFileIds, outputFileRecords);
+      return processFileSwap(state, inputFileIds, outputStirlingFileStubs);
     }
 
     case 'UNDO_CONSUME_FILES': {
-      const { inputFileRecords, outputFileIds } = action.payload;
+      const { inputStirlingFileStubs, outputFileIds } = action.payload;
-      return processFileSwap(state, outputFileIds, inputFileRecords);
+      return processFileSwap(state, outputFileIds, inputStirlingFileStubs);
     }
 
     case 'RESET_CONTEXT': {

frontend/src/contexts/file/fileActions.ts

@@ -3,10 +3,10 @@
  */
 
 import {
-  FileRecord,
+  StirlingFileStub,
   FileContextAction,
   FileContextState,
-  toFileRecord,
+  toStirlingFileStub,
   createFileId,
   createQuickKey
 } from '../../types/fileContext';
@@ -109,8 +109,8 @@ export async function addFiles(
   await addFilesMutex.lock();
 
   try {
-  const fileRecords: FileRecord[] = [];
+    const stirlingFileStubs: StirlingFileStub[] = [];
-  const addedFiles: AddedFile[] = [];
+    const addedFiles: AddedFile[] = [];
 
   // Build quickKey lookup from existing files for deduplication
   const existingQuickKeys = buildQuickKeySet(stateRef.current.files.byId);
@@ -163,7 +163,7 @@ export async function addFiles(
         }
 
         // Create record with immediate thumbnail and page metadata
-        const record = toFileRecord(file, fileId);
+        const record = toStirlingFileStub(file, fileId);
         if (thumbnail) {
           record.thumbnailUrl = thumbnail;
           // Track blob URLs for cleanup (images return blob URLs that need revocation)
@@ -184,7 +184,7 @@ export async function addFiles(
         }
 
         existingQuickKeys.add(quickKey);
-        fileRecords.push(record);
+        stirlingFileStubs.push(record);
         addedFiles.push({ file, id: fileId, thumbnail });
         }
       break;
@@ -205,7 +205,7 @@ export async function addFiles(
         const fileId = createFileId();
         filesRef.current.set(fileId, file);
 
-        const record = toFileRecord(file, fileId);
+        const record = toStirlingFileStub(file, fileId);
         if (thumbnail) {
           record.thumbnailUrl = thumbnail;
           // Track blob URLs for cleanup (images return blob URLs that need revocation)
@@ -226,7 +226,7 @@ export async function addFiles(
         }
 
         existingQuickKeys.add(quickKey);
-        fileRecords.push(record);
+        stirlingFileStubs.push(record);
         addedFiles.push({ file, id: fileId, thumbnail });
       }
       break;
@@ -254,7 +254,7 @@ export async function addFiles(
 
         filesRef.current.set(fileId, file);
 
-        const record = toFileRecord(file, fileId);
+        const record = toStirlingFileStub(file, fileId);
 
         // Generate processedFile metadata for stored files
         let pageCount: number = 1;
@@ -301,7 +301,7 @@ export async function addFiles(
         }
 
         existingQuickKeys.add(quickKey);
-        fileRecords.push(record);
+        stirlingFileStubs.push(record);
         addedFiles.push({ file, id: fileId, thumbnail: metadata.thumbnail });
 
       }
@@ -310,9 +310,9 @@ export async function addFiles(
   }
 
   // Dispatch ADD_FILES action if we have new files
-  if (fileRecords.length > 0) {
+  if (stirlingFileStubs.length > 0) {
-    dispatch({ type: 'ADD_FILES', payload: { fileRecords } });
+    dispatch({ type: 'ADD_FILES', payload: { stirlingFileStubs } });
-    if (DEBUG) console.log(`📄 addFiles(${kind}): Successfully added ${fileRecords.length} files`);
+    if (DEBUG) console.log(`📄 addFiles(${kind}): Successfully added ${stirlingFileStubs.length} files`);
   }
 
   return addedFiles;
@@ -328,7 +328,7 @@ export async function addFiles(
 async function processFilesIntoRecords(
   files: File[],
   filesRef: React.MutableRefObject<Map<FileId, File>>
-): Promise<Array<{ record: FileRecord; file: File; fileId: FileId; thumbnail?: string }>> {
+): Promise<Array<{ record: StirlingFileStub; file: File; fileId: FileId; thumbnail?: string }>> {
   return Promise.all(
     files.map(async (file) => {
       const fileId = createFileId();
@@ -347,7 +347,7 @@ async function processFilesIntoRecords(
         if (DEBUG) console.warn(`📄 Failed to generate thumbnail for file ${file.name}:`, error);
       }
 
-      const record = toFileRecord(file, fileId);
+      const record = toStirlingFileStub(file, fileId);
       if (thumbnail) {
         record.thumbnailUrl = thumbnail;
       }
@@ -365,10 +365,10 @@ async function processFilesIntoRecords(
  * Helper function to persist files to IndexedDB
  */
 async function persistFilesToIndexedDB(
-  fileRecords: Array<{ file: File; fileId: FileId; thumbnail?: string }>,
+  stirlingFileStubs: Array<{ file: File; fileId: FileId; thumbnail?: string }>,
   indexedDB: { saveFile: (file: File, fileId: FileId, existingThumbnail?: string) => Promise<any> }
 ): Promise<void> {
-  await Promise.all(fileRecords.map(async ({ file, fileId, thumbnail }) => {
+  await Promise.all(stirlingFileStubs.map(async ({ file, fileId, thumbnail }) => {
     try {
       await indexedDB.saveFile(file, fileId, thumbnail);
     } catch (error) {
@@ -383,7 +383,6 @@ async function persistFilesToIndexedDB(
 export async function consumeFiles(
   inputFileIds: FileId[],
   outputFiles: File[],
-  stateRef: React.MutableRefObject<FileContextState>,
   filesRef: React.MutableRefObject<Map<FileId, File>>,
   dispatch: React.Dispatch<FileContextAction>,
   indexedDB?: { saveFile: (file: File, fileId: FileId, existingThumbnail?: string) => Promise<any> } | null
@@ -391,11 +390,11 @@ export async function consumeFiles(
   if (DEBUG) console.log(`📄 consumeFiles: Processing ${inputFileIds.length} input files, ${outputFiles.length} output files`);
 
   // Process output files with thumbnails and metadata
-  const outputFileRecords = await processFilesIntoRecords(outputFiles, filesRef);
+  const outputStirlingFileStubs = await processFilesIntoRecords(outputFiles, filesRef);
 
   // Persist output files to IndexedDB if available
   if (indexedDB) {
-    await persistFilesToIndexedDB(outputFileRecords, indexedDB);
+    await persistFilesToIndexedDB(outputStirlingFileStubs, indexedDB);
   }
 
   // Dispatch the consume action
@@ -403,21 +402,21 @@ export async function consumeFiles(
     type: 'CONSUME_FILES',
     payload: {
       inputFileIds,
-      outputFileRecords: outputFileRecords.map(({ record }) => record)
+      outputStirlingFileStubs: outputStirlingFileStubs.map(({ record }) => record)
     }
   });
 
-  if (DEBUG) console.log(`📄 consumeFiles: Successfully consumed files - removed ${inputFileIds.length} inputs, added ${outputFileRecords.length} outputs`);
+  if (DEBUG) console.log(`📄 consumeFiles: Successfully consumed files - removed ${inputFileIds.length} inputs, added ${outputStirlingFileStubs.length} outputs`);
-  
+
   // Return the output file IDs for undo tracking
-  return outputFileRecords.map(({ fileId }) => fileId);
+  return outputStirlingFileStubs.map(({ fileId }) => fileId);
 }
 
 /**
  * Helper function to restore files to filesRef and manage IndexedDB cleanup
  */
 async function restoreFilesAndCleanup(
-  filesToRestore: Array<{ file: File; record: FileRecord }>,
+  filesToRestore: Array<{ file: File; record: StirlingFileStub }>,
   fileIdsToRemove: FileId[],
   filesRef: React.MutableRefObject<Map<FileId, File>>,
   indexedDB?: { deleteFile: (fileId: FileId) => Promise<void> } | null
@@ -440,7 +439,7 @@ async function restoreFilesAndCleanup(
         if (DEBUG) console.warn(`📄 Skipping empty file ${file.name}`);
         return;
       }
-      
+
       // Restore the file to filesRef
       if (DEBUG) console.log(`📄 Restoring file ${file.name} with id ${record.id} to filesRef`);
       filesRef.current.set(record.id, file);
@@ -455,7 +454,7 @@ async function restoreFilesAndCleanup(
         throw error; // Re-throw to trigger rollback
       })
     );
-    
+
     // Execute all IndexedDB operations
     await Promise.all(indexedDBPromises);
   }
@@ -466,28 +465,28 @@ async function restoreFilesAndCleanup(
  */
 export async function undoConsumeFiles(
   inputFiles: File[],
-  inputFileRecords: FileRecord[],
+  inputStirlingFileStubs: StirlingFileStub[],
   outputFileIds: FileId[],
   stateRef: React.MutableRefObject<FileContextState>,
   filesRef: React.MutableRefObject<Map<FileId, File>>,
   dispatch: React.Dispatch<FileContextAction>,
   indexedDB?: { saveFile: (file: File, fileId: FileId, existingThumbnail?: string) => Promise<any>; deleteFile: (fileId: FileId) => Promise<void> } | null
 ): Promise<void> {
-  if (DEBUG) console.log(`📄 undoConsumeFiles: Restoring ${inputFileRecords.length} input files, removing ${outputFileIds.length} output files`);
+  if (DEBUG) console.log(`📄 undoConsumeFiles: Restoring ${inputStirlingFileStubs.length} input files, removing ${outputFileIds.length} output files`);
 
   // Validate inputs
-  if (inputFiles.length !== inputFileRecords.length) {
+  if (inputFiles.length !== inputStirlingFileStubs.length) {
-    throw new Error(`Mismatch between input files (${inputFiles.length}) and records (${inputFileRecords.length})`);
+    throw new Error(`Mismatch between input files (${inputFiles.length}) and records (${inputStirlingFileStubs.length})`);
   }
 
   // Create a backup of current filesRef state for rollback
   const backupFilesRef = new Map(filesRef.current);
-  
+
   try {
     // Prepare files to restore
     const filesToRestore = inputFiles.map((file, index) => ({
       file,
-      record: inputFileRecords[index]
+      record: inputStirlingFileStubs[index]
     }));
 
     // Restore input files and clean up output files
@@ -502,13 +501,13 @@ export async function undoConsumeFiles(
     dispatch({
       type: 'UNDO_CONSUME_FILES',
       payload: {
-        inputFileRecords,
+        inputStirlingFileStubs,
         outputFileIds
       }
     });
 
-    if (DEBUG) console.log(`📄 undoConsumeFiles: Successfully undone consume operation - restored ${inputFileRecords.length} inputs, removed ${outputFileIds.length} outputs`);
+    if (DEBUG) console.log(`📄 undoConsumeFiles: Successfully undone consume operation - restored ${inputStirlingFileStubs.length} inputs, removed ${outputFileIds.length} outputs`);
-    
+
   } catch (error) {
     // Rollback filesRef to previous state
     if (DEBUG) console.error('📄 undoConsumeFiles: Error during undo, rolling back filesRef', error);

frontend/src/contexts/file/fileHooks.ts

@@ -9,7 +9,7 @@ import {
   FileContextStateValue,
   FileContextActionsValue
 } from './contexts';
-import { FileRecord } from '../../types/fileContext';
+import { StirlingFileStub, StirlingFile } from '../../types/fileContext';
 import { FileId } from '../../types/file';
 
 /**
@@ -38,13 +38,13 @@ export function useFileActions(): FileContextActionsValue {
 /**
  * Hook for current/primary file (first in list)
  */
-export function useCurrentFile(): { file?: File; record?: FileRecord } {
+export function useCurrentFile(): { file?: File; record?: StirlingFileStub } {
   const { state, selectors } = useFileState();
 
   const primaryFileId = state.files.ids[0];
   return useMemo(() => ({
     file: primaryFileId ? selectors.getFile(primaryFileId) : undefined,
-    record: primaryFileId ? selectors.getFileRecord(primaryFileId) : undefined
+    record: primaryFileId ? selectors.getStirlingFileStub(primaryFileId) : undefined
   }), [primaryFileId, selectors]);
 }
 
@@ -87,7 +87,7 @@ export function useFileManagement() {
     addFiles: actions.addFiles,
     removeFiles: actions.removeFiles,
     clearAllFiles: actions.clearAllFiles,
-    updateFileRecord: actions.updateFileRecord,
+    updateStirlingFileStub: actions.updateStirlingFileStub,
     reorderFiles: actions.reorderFiles
   }), [actions]);
 }
@@ -111,24 +111,24 @@ export function useFileUI() {
 /**
  * Hook for specific file by ID (optimized for individual file access)
  */
-export function useFileRecord(fileId: FileId): { file?: File; record?: FileRecord } {
+export function useStirlingFileStub(fileId: FileId): { file?: File; record?: StirlingFileStub } {
   const { selectors } = useFileState();
 
   return useMemo(() => ({
     file: selectors.getFile(fileId),
-    record: selectors.getFileRecord(fileId)
+    record: selectors.getStirlingFileStub(fileId)
   }), [fileId, selectors]);
 }
 
 /**
  * Hook for all files (use sparingly - causes re-renders on file list changes)
  */
-export function useAllFiles(): { files: File[]; records: FileRecord[]; fileIds: FileId[] } {
+export function useAllFiles(): { files: StirlingFile[]; records: StirlingFileStub[]; fileIds: FileId[] } {
   const { state, selectors } = useFileState();
 
   return useMemo(() => ({
     files: selectors.getFiles(),
-    records: selectors.getFileRecords(),
+    records: selectors.getStirlingFileStubs(),
     fileIds: state.files.ids
   }), [state.files.ids, selectors]);
 }
@@ -136,12 +136,12 @@ export function useAllFiles(): { files: File[]; records: FileRecord[]; fileIds:
 /**
  * Hook for selected files (optimized for selection-based UI)
  */
-export function useSelectedFiles(): { files: File[]; records: FileRecord[]; fileIds: FileId[] } {
+export function useSelectedFiles(): { files: StirlingFile[]; records: StirlingFileStub[]; fileIds: FileId[] } {
   const { state, selectors } = useFileState();
 
   return useMemo(() => ({
     files: selectors.getSelectedFiles(),
-    records: selectors.getSelectedFileRecords(),
+    records: selectors.getSelectedStirlingFileStubs(),
     fileIds: state.ui.selectedFileIds
   }), [state.ui.selectedFileIds, selectors]);
 }

frontend/src/contexts/file/fileSelectors.ts

@@ -4,9 +4,11 @@
 
 import { FileId } from '../../types/file';
 import {
-  FileRecord,
+  StirlingFileStub,
   FileContextState,
-  FileContextSelectors
+  FileContextSelectors,
+  StirlingFile,
+  createStirlingFile
 } from '../../types/fileContext';
 
 /**
@@ -17,16 +19,24 @@ export function createFileSelectors(
   filesRef: React.MutableRefObject<Map<FileId, File>>
 ): FileContextSelectors {
   return {
-    getFile: (id: FileId) => filesRef.current.get(id),
+    getFile: (id: FileId) => {
+      const file = filesRef.current.get(id);
+      return file ? createStirlingFile(file, id) : undefined;
+    },
 
     getFiles: (ids?: FileId[]) => {
       const currentIds = ids || stateRef.current.files.ids;
-      return currentIds.map(id => filesRef.current.get(id)).filter(Boolean) as File[];
+      return currentIds
+        .map(id => {
+          const file = filesRef.current.get(id);
+          return file ? createStirlingFile(file, id) : undefined;
+        })
+        .filter(Boolean) as StirlingFile[];
     },
 
-    getFileRecord: (id: FileId) => stateRef.current.files.byId[id],
+    getStirlingFileStub: (id: FileId) => stateRef.current.files.byId[id],
 
-    getFileRecords: (ids?: FileId[]) => {
+    getStirlingFileStubs: (ids?: FileId[]) => {
       const currentIds = ids || stateRef.current.files.ids;
       return currentIds.map(id => stateRef.current.files.byId[id]).filter(Boolean);
     },
@@ -35,11 +45,14 @@ export function createFileSelectors(
 
     getSelectedFiles: () => {
       return stateRef.current.ui.selectedFileIds
-        .map(id => filesRef.current.get(id))
+        .map(id => {
-        .filter(Boolean) as File[];
+          const file = filesRef.current.get(id);
+          return file ? createStirlingFile(file, id) : undefined;
+        })
+        .filter(Boolean) as StirlingFile[];
     },
 
-    getSelectedFileRecords: () => {
+    getSelectedStirlingFileStubs: () => {
       return stateRef.current.ui.selectedFileIds
         .map(id => stateRef.current.files.byId[id])
         .filter(Boolean);
@@ -52,26 +65,21 @@ export function createFileSelectors(
 
     getPinnedFiles: () => {
       return Array.from(stateRef.current.pinnedFiles)
-        .map(id => filesRef.current.get(id))
+        .map(id => {
-        .filter(Boolean) as File[];
+          const file = filesRef.current.get(id);
+          return file ? createStirlingFile(file, id) : undefined;
+        })
+        .filter(Boolean) as StirlingFile[];
     },
 
-    getPinnedFileRecords: () => {
+    getPinnedStirlingFileStubs: () => {
       return Array.from(stateRef.current.pinnedFiles)
         .map(id => stateRef.current.files.byId[id])
         .filter(Boolean);
     },
 
-    isFilePinned: (file: File) => {
+    isFilePinned: (file: StirlingFile) => {
-      // Find FileId by matching File object properties
+      return stateRef.current.pinnedFiles.has(file.fileId);
-      const fileId = (Object.keys(stateRef.current.files.byId) as FileId[]).find(id => {
-        const storedFile = filesRef.current.get(id);
-        return storedFile &&
-               storedFile.name === file.name &&
-               storedFile.size === file.size &&
-               storedFile.lastModified === file.lastModified;
-      });
-      return fileId ? stateRef.current.pinnedFiles.has(fileId) : false;
     },
 
     // Stable signature for effects - prevents unnecessary re-renders
@@ -90,9 +98,9 @@ export function createFileSelectors(
 /**
  * Helper for building quickKey sets for deduplication
  */
-export function buildQuickKeySet(fileRecords: Record<FileId, FileRecord>): Set<string> {
+export function buildQuickKeySet(stirlingFileStubs: Record<FileId, StirlingFileStub>): Set<string> {
   const quickKeys = new Set<string>();
-  Object.values(fileRecords).forEach(record => {
+  Object.values(stirlingFileStubs).forEach(record => {
     if (record.quickKey) {
       quickKeys.add(record.quickKey);
     }
@@ -119,7 +127,7 @@ export function buildQuickKeySetFromMetadata(metadata: Array<{ name: string; siz
 export function getPrimaryFile(
   stateRef: React.MutableRefObject<FileContextState>,
   filesRef: React.MutableRefObject<Map<FileId, File>>
-): { file?: File; record?: FileRecord } {
+): { file?: File; record?: StirlingFileStub } {
   const primaryFileId = stateRef.current.files.ids[0];
   if (!primaryFileId) return {};
 

frontend/src/contexts/file/lifecycle.ts

@@ -3,7 +3,7 @@
  */
 
 import { FileId } from '../../types/file';
-import { FileContextAction, FileRecord, ProcessedFilePage } from '../../types/fileContext';
+import { FileContextAction, StirlingFileStub, ProcessedFilePage } from '../../types/fileContext';
 
 const DEBUG = process.env.NODE_ENV === 'development';
 
@@ -166,7 +166,7 @@ export class FileLifecycleManager {
   /**
    * Update file record with race condition guards
    */
-  updateFileRecord = (fileId: FileId, updates: Partial<FileRecord>, stateRef?: React.MutableRefObject<any>): void => {
+  updateStirlingFileStub = (fileId: FileId, updates: Partial<StirlingFileStub>, stateRef?: React.MutableRefObject<any>): void => {
     // Guard against updating removed files (race condition protection)
     if (!this.filesRef.current.has(fileId)) {
       if (DEBUG) console.warn(`🗂️ Attempted to update removed file (filesRef): ${fileId}`);

frontend/src/hooks/tools/convert/useConvertParametersAutoDetection.test.ts

@@ -347,9 +347,9 @@ describe('useConvertParameters - Auto Detection & Smart Conversion', () => {
 
       const malformedFiles: Array<{name: string}> = [
         { name: 'valid.pdf' },
-        // @ts-ignore - Testing runtime resilience
+        // @ts-expect-error - Testing runtime resilience
         { name: null },
-        // @ts-ignore
+        // @ts-expect-error - Testing runtime resilience
         { name: undefined }
       ];
 

frontend/src/hooks/tools/shared/useBaseTool.ts

@@ -4,10 +4,11 @@ import { useEndpointEnabled } from '../../useEndpointConfig';
 import { BaseToolProps } from '../../../types/tool';
 import { ToolOperationHook } from './useToolOperation';
 import { BaseParametersHook } from './useBaseParameters';
+import { StirlingFile } from '../../../types/fileContext';
 
 interface BaseToolReturn<TParams> {
   // File management
-  selectedFiles: File[];
+  selectedFiles: StirlingFile[];
 
   // Tool-specific hooks
   params: BaseParametersHook<TParams>;

frontend/src/hooks/tools/shared/useToolOperation.ts

@@ -6,10 +6,8 @@ import { useToolState, type ProcessingProgress } from './useToolState';
 import { useToolApiCalls, type ApiCallsConfig } from './useToolApiCalls';
 import { useToolResources } from './useToolResources';
 import { extractErrorMessage } from '../../../utils/toolErrorHandler';
-import { createOperation } from '../../../utils/toolOperationTracker';
+import { StirlingFile, extractFiles, FileId, StirlingFileStub } from '../../../types/fileContext';
 import { ResponseHandler } from '../../../utils/toolResponseProcessor';
-import { FileId } from '../../../types/file';
-import { FileRecord } from '../../../types/fileContext';
 
 // Re-export for backwards compatibility
 export type { ProcessingProgress, ResponseHandler };
@@ -111,7 +109,7 @@ export interface ToolOperationHook<TParams = void> {
   progress: ProcessingProgress | null;
 
   // Actions
-  executeOperation: (params: TParams, selectedFiles: File[]) => Promise<void>;
+  executeOperation: (params: TParams, selectedFiles: StirlingFile[]) => Promise<void>;
   resetResults: () => void;
   clearError: () => void;
   cancelOperation: () => void;
@@ -137,7 +135,7 @@ export const useToolOperation = <TParams>(
   config: ToolOperationConfig<TParams>
 ): ToolOperationHook<TParams> => {
   const { t } = useTranslation();
-  const { recordOperation, markOperationApplied, markOperationFailed, addFiles, consumeFiles, undoConsumeFiles, findFileId, actions: fileActions, selectors } = useFileContext();
+  const { addFiles, consumeFiles, undoConsumeFiles, actions: fileActions, selectors } = useFileContext();
 
   // Composed hooks
   const { state, actions } = useToolState();
@@ -147,13 +145,13 @@ export const useToolOperation = <TParams>(
   // Track last operation for undo functionality
   const lastOperationRef = useRef<{
     inputFiles: File[];
-    inputFileRecords: FileRecord[];
+    inputStirlingFileStubs: StirlingFileStub[];
     outputFileIds: FileId[];
   } | null>(null);
 
   const executeOperation = useCallback(async (
     params: TParams,
-    selectedFiles: File[]
+    selectedFiles: StirlingFile[]
   ): Promise<void> => {
     // Validation
     if (selectedFiles.length === 0) {
@@ -167,9 +165,6 @@ export const useToolOperation = <TParams>(
       return;
     }
 
-    // Setup operation tracking
-    const { operation, operationId, fileId } = createOperation(config.operationType, params, selectedFiles);
-    recordOperation(fileId, operation);
 
     // Reset state
     actions.setLoading(true);
@@ -180,8 +175,11 @@ export const useToolOperation = <TParams>(
     try {
       let processedFiles: File[];
 
+      // Convert StirlingFile to regular File objects for API processing
+      const validRegularFiles = extractFiles(validFiles);
+
       switch (config.toolType) {
-        case ToolType.singleFile:
+        case ToolType.singleFile: {
           // Individual file processing - separate API call per file
           const apiCallsConfig: ApiCallsConfig<TParams> = {
             endpoint: config.endpoint,
@@ -192,17 +190,18 @@ export const useToolOperation = <TParams>(
           };
           processedFiles = await processFiles(
             params,
-            validFiles,
+            validRegularFiles,
             apiCallsConfig,
             actions.setProgress,
             actions.setStatus
           );
           break;
+        }
 
-        case ToolType.multiFile:
+        case ToolType.multiFile: {
           // Multi-file processing - single API call with all files
           actions.setStatus('Processing files...');
-          const formData = config.buildFormData(params, validFiles);
+          const formData = config.buildFormData(params, validRegularFiles);
           const endpoint = typeof config.endpoint === 'function' ? config.endpoint(params) : config.endpoint;
 
           const response = await axios.post(endpoint, formData, { responseType: 'blob' });
@@ -210,11 +209,11 @@ export const useToolOperation = <TParams>(
           // Multi-file responses are typically ZIP files that need extraction, but some may return single PDFs
           if (config.responseHandler) {
             // Use custom responseHandler for multi-file (handles ZIP extraction)
-            processedFiles = await config.responseHandler(response.data, validFiles);
+            processedFiles = await config.responseHandler(response.data, validRegularFiles);
           } else if (response.data.type === 'application/pdf' ||
-                     (response.headers && response.headers['content-type'] === 'application/pdf')) {
+                    (response.headers && response.headers['content-type'] === 'application/pdf')) {
             // Single PDF response (e.g. split with merge option) - use original filename
-            const originalFileName = validFiles[0]?.name || 'document.pdf';
+            const originalFileName = validRegularFiles[0]?.name || 'document.pdf';
             const singleFile = new File([response.data], originalFileName, { type: 'application/pdf' });
             processedFiles = [singleFile];
           } else {
@@ -227,10 +226,11 @@ export const useToolOperation = <TParams>(
             }
           }
           break;
+        }
 
         case ToolType.custom:
           actions.setStatus('Processing files...');
-          processedFiles = await config.customProcessor(params, validFiles);
+          processedFiles = await config.customProcessor(params, validRegularFiles);
           break;
       }
 
@@ -250,46 +250,40 @@ export const useToolOperation = <TParams>(
 
         // Replace input files with processed files (consumeFiles handles pinning)
         const inputFileIds: FileId[] = [];
-        const inputFileRecords: FileRecord[] = [];
+        const inputStirlingFileStubs: StirlingFileStub[] = [];
         
         // Build parallel arrays of IDs and records for undo tracking
         for (const file of validFiles) {
-          const fileId = findFileId(file);
+          const fileId = file.fileId;
-          if (fileId) {
+          const record = selectors.getStirlingFileStub(fileId);
-            const record = selectors.getFileRecord(fileId);
+          if (record) {
-            if (record) {
+            inputFileIds.push(fileId);
-              inputFileIds.push(fileId);
+            inputStirlingFileStubs.push(record);
-              inputFileRecords.push(record);
-            } else {
-              console.warn(`No file record found for file: ${file.name}`);
-            }
           } else {
-            console.warn(`No file ID found for file: ${file.name}`);
+            console.warn(`No file stub found for file: ${file.name}`);
           }
         }
-        
+
         const outputFileIds = await consumeFiles(inputFileIds, processedFiles);
-        
+
         // Store operation data for undo (only store what we need to avoid memory bloat)
         lastOperationRef.current = {
-          inputFiles: validFiles, // Keep original File objects for undo
+          inputFiles: extractFiles(validFiles), // Convert to File objects for undo
-          inputFileRecords: inputFileRecords.map(record => ({ ...record })), // Deep copy to avoid reference issues
+          inputStirlingFileStubs: inputStirlingFileStubs.map(record => ({ ...record })), // Deep copy to avoid reference issues
           outputFileIds
         };
 
-        markOperationApplied(fileId, operationId);
       }
 
     } catch (error: any) {
       const errorMessage = config.getErrorMessage?.(error) || extractErrorMessage(error);
       actions.setError(errorMessage);
       actions.setStatus('');
-      markOperationFailed(fileId, operationId, errorMessage);
     } finally {
       actions.setLoading(false);
       actions.setProgress(null);
     }
-  }, [t, config, actions, recordOperation, markOperationApplied, markOperationFailed, addFiles, consumeFiles, findFileId, processFiles, generateThumbnails, createDownloadInfo, cleanupBlobUrls, extractZipFiles, extractAllZipFiles]);
+  }, [t, config, actions, addFiles, consumeFiles, processFiles, generateThumbnails, createDownloadInfo, cleanupBlobUrls, extractZipFiles, extractAllZipFiles]);
 
   const cancelOperation = useCallback(() => {
     cancelApiCalls();
@@ -318,10 +312,10 @@ export const useToolOperation = <TParams>(
       return;
     }
 
-    const { inputFiles, inputFileRecords, outputFileIds } = lastOperationRef.current;
+    const { inputFiles, inputStirlingFileStubs, outputFileIds } = lastOperationRef.current;
 
     // Validate that we have data to undo
-    if (inputFiles.length === 0 || inputFileRecords.length === 0) {
+    if (inputFiles.length === 0 || inputStirlingFileStubs.length === 0) {
       actions.setError(t('invalidUndoData', 'Cannot undo: invalid operation data'));
       return;
     }
@@ -333,18 +327,19 @@ export const useToolOperation = <TParams>(
 
     try {
       // Undo the consume operation
-      await undoConsumeFiles(inputFiles, inputFileRecords, outputFileIds);
+      await undoConsumeFiles(inputFiles, inputStirlingFileStubs, outputFileIds);
       
+
       // Clear results and operation tracking
       resetResults();
       lastOperationRef.current = null;
-      
+
       // Show success message
       actions.setStatus(t('undoSuccess', 'Operation undone successfully'));
-      
+
     } catch (error: any) {
       let errorMessage = extractErrorMessage(error);
-      
+
       // Provide more specific error messages based on error type
       if (error.message?.includes('Mismatch between input files')) {
         errorMessage = t('undoDataMismatch', 'Cannot undo: operation data is corrupted');
@@ -353,9 +348,9 @@ export const useToolOperation = <TParams>(
       } else if (error.name === 'QuotaExceededError') {
         errorMessage = t('undoQuotaError', 'Cannot undo: insufficient storage space');
       }
-      
+
       actions.setError(`${t('undoFailed', 'Failed to undo operation')}: ${errorMessage}`);
-      
+
       // Don't clear the operation data if undo failed - user might want to try again
     }
   }, [undoConsumeFiles, resetResults, actions, t]);

frontend/src/hooks/useFileManager.ts

@@ -2,7 +2,7 @@ import { useState, useCallback } from 'react';
 import { useIndexedDB } from '../contexts/IndexedDBContext';
 import { FileMetadata } from '../types/file';
 import { generateThumbnailForFile } from '../utils/thumbnailUtils';
-import { FileId } from '../types/file';
+import { FileId } from '../types/fileContext';
 
 export const useFileManager = () => {
   const [loading, setLoading] = useState(false);

frontend/src/hooks/useFileWithUrl.ts

@@ -1,4 +1,5 @@
 import { useMemo } from 'react';
+import { isFileObject } from '../types/fileContext';
 
 /**
  * Hook to convert a File object to { file: File; url: string } format
@@ -8,8 +9,8 @@ export function useFileWithUrl(file: File | Blob | null): { file: File | Blob; u
   return useMemo(() => {
     if (!file) return null;
 
-    // Validate that file is a proper File or Blob object
+    // Validate that file is a proper File, StirlingFile, or Blob object
-    if (!(file instanceof File) && !(file instanceof Blob)) {
+    if (!isFileObject(file) && !(file instanceof Blob)) {
       console.warn('useFileWithUrl: Expected File or Blob, got:', file);
       return null;
     }

frontend/src/hooks/useIndexedDBThumbnail.ts

@@ -2,6 +2,7 @@ import { useState, useEffect } from "react";
 import { FileMetadata } from "../types/file";
 import { useIndexedDB } from "../contexts/IndexedDBContext";
 import { generateThumbnailForFile } from "../utils/thumbnailUtils";
+import { FileId } from "../types/fileContext";
 
 /**
  * Calculate optimal scale for thumbnail generation
@@ -53,7 +54,7 @@ export function useIndexedDBThumbnail(file: FileMetadata | undefined | null): {
 
           // Try to load file from IndexedDB using new context
           if (file.id && indexedDB) {
-            const loadedFile = await indexedDB.loadFile(file.id);
+            const loadedFile = await indexedDB.loadFile(file.id as FileId);
             if (!loadedFile) {
               throw new Error('File not found in IndexedDB');
             }
@@ -70,7 +71,7 @@ export function useIndexedDBThumbnail(file: FileMetadata | undefined | null): {
             // Save thumbnail to IndexedDB for persistence
             if (file.id && indexedDB && thumbnail) {
               try {
-                await indexedDB.updateThumbnail(file.id, thumbnail);
+                await indexedDB.updateThumbnail(file.id as FileId, thumbnail);
               } catch (error) {
                 console.warn('Failed to save thumbnail to IndexedDB:', error);
               }

frontend/src/hooks/usePDFProcessor.ts

@@ -1,6 +1,7 @@
 import { useState, useCallback } from 'react';
 import { PDFDocument, PDFPage } from '../types/pageEditor';
 import { pdfWorkerManager } from '../services/pdfWorkerManager';
+import { createQuickKey } from '../types/fileContext';
 
 export function usePDFProcessor() {
   const [loading, setLoading] = useState(false);
@@ -75,7 +76,7 @@ export function usePDFProcessor() {
       // Create pages without thumbnails initially - load them lazily
       for (let i = 1; i <= totalPages; i++) {
         pages.push({
-          id: `${file.name}-page-${i}`,
+          id: `${createQuickKey(file)}-page-${i}`,
           pageNumber: i,
           originalPageNumber: i,
           thumbnail: null, // Will be loaded lazily

frontend/src/hooks/usePdfSignatureDetection.ts

@@ -1,13 +1,14 @@
 import { useState, useEffect } from 'react';
 import * as pdfjsLib from 'pdfjs-dist';
 import { pdfWorkerManager } from '../services/pdfWorkerManager';
+import { StirlingFile } from '../types/fileContext';
 
 export interface PdfSignatureDetectionResult {
   hasDigitalSignatures: boolean;
   isChecking: boolean;
 }
 
-export const usePdfSignatureDetection = (files: File[]): PdfSignatureDetectionResult => {
+export const usePdfSignatureDetection = (files: StirlingFile[]): PdfSignatureDetectionResult => {
   const [hasDigitalSignatures, setHasDigitalSignatures] = useState(false);
   const [isChecking, setIsChecking] = useState(false);
 

frontend/src/hooks/useThumbnailGeneration.ts

@@ -1,5 +1,6 @@
 import { useCallback, useRef } from 'react';
 import { thumbnailGenerationService } from '../services/thumbnailGenerationService';
+import { createQuickKey } from '../types/fileContext';
 import { FileId } from '../types/file';
 
 // Request queue to handle concurrent thumbnail requests
@@ -71,8 +72,8 @@ async function processRequestQueue() {
 
           console.log(`📸 Batch generating ${requests.length} thumbnails for pages: ${pageNumbers.slice(0, 5).join(', ')}${pageNumbers.length > 5 ? '...' : ''}`);
 
-          // Use file name as fileId for PDF document caching
+          // Use quickKey for PDF document caching (same metadata, consistent format)
-          const fileId = file.name + '_' + file.size + '_' + file.lastModified as FileId;
+          const fileId = createQuickKey(file) as FileId;
 
           const results = await thumbnailGenerationService.generateThumbnails(
             fileId,

frontend/src/services/enhancedPDFProcessingService.ts

@@ -5,6 +5,7 @@ import { FileHasher } from '../utils/fileHash';
 import { FileAnalyzer } from './fileAnalyzer';
 import { ProcessingErrorHandler } from './processingErrorHandler';
 import { pdfWorkerManager } from './pdfWorkerManager';
+import { createQuickKey } from '../types/fileContext';
 
 export class EnhancedPDFProcessingService {
   private static instance: EnhancedPDFProcessingService;
@@ -201,7 +202,7 @@ export class EnhancedPDFProcessingService {
         const thumbnail = await this.renderPageThumbnail(page, config.thumbnailQuality);
 
         pages.push({
-          id: `${file.name}-page-${i}`,
+          id: `${createQuickKey(file)}-page-${i}`,
           pageNumber: i,
           thumbnail,
           rotation: 0,
@@ -251,7 +252,7 @@ export class EnhancedPDFProcessingService {
       const thumbnail = await this.renderPageThumbnail(page, config.thumbnailQuality);
 
       pages.push({
-        id: `${file.name}-page-${i}`,
+        id: `${createQuickKey(file)}-page-${i}`,
         pageNumber: i,
         thumbnail,
         rotation: 0,
@@ -266,7 +267,7 @@ export class EnhancedPDFProcessingService {
     // Create placeholder pages for remaining pages
     for (let i = priorityCount + 1; i <= totalPages; i++) {
       pages.push({
-        id: `${file.name}-page-${i}`,
+        id: `${createQuickKey(file)}-page-${i}`,
         pageNumber: i,
         thumbnail: null, // Will be loaded lazily
         rotation: 0,
@@ -313,7 +314,7 @@ export class EnhancedPDFProcessingService {
       const thumbnail = await this.renderPageThumbnail(page, config.thumbnailQuality);
 
       pages.push({
-        id: `${file.name}-page-${i}`,
+        id: `${createQuickKey(file)}-page-${i}`,
         pageNumber: i,
         thumbnail,
         rotation: 0,
@@ -334,7 +335,7 @@ export class EnhancedPDFProcessingService {
     // Create placeholders for remaining pages
     for (let i = firstChunkEnd + 1; i <= totalPages; i++) {
       pages.push({
-        id: `${file.name}-page-${i}`,
+        id: `${createQuickKey(file)}-page-${i}`,
         pageNumber: i,
         thumbnail: null,
         rotation: 0,
@@ -368,7 +369,7 @@ export class EnhancedPDFProcessingService {
     const pages: PDFPage[] = [];
     for (let i = 1; i <= totalPages; i++) {
       pages.push({
-        id: `${file.name}-page-${i}`,
+        id: `${createQuickKey(file)}-page-${i}`,
         pageNumber: i,
         thumbnail: null,
         rotation: 0,
@@ -459,11 +460,12 @@ export class EnhancedPDFProcessingService {
       case 'failed':
         this.metrics.failedFiles++;
         break;
-      case 'cacheHit':
+      case 'cacheHit': {
         // Update cache hit rate
         const totalAttempts = this.metrics.totalFiles + 1;
         this.metrics.cacheHitRate = (this.metrics.cacheHitRate * this.metrics.totalFiles + 1) / totalAttempts;
         break;
+      }
     }
   }
 

frontend/src/services/fileAnalyzer.ts

@@ -148,15 +148,17 @@ export class FileAnalyzer {
       case 'immediate_full':
         return pageCount * baseTime;
 
-      case 'priority_pages':
+      case 'priority_pages': {
         // Estimate time for priority pages (first 10)
         const priorityPages = Math.min(pageCount, 10);
         return priorityPages * baseTime;
+      }
 
-      case 'progressive_chunked':
+      case 'progressive_chunked': {
         // Estimate time for first chunk (20 pages)
         const firstChunk = Math.min(pageCount, 20);
         return firstChunk * baseTime;
+      }
 
       default:
         return pageCount * baseTime;

frontend/src/services/pdfProcessingService.ts

@@ -1,6 +1,7 @@
 import { ProcessedFile, ProcessingState, PDFPage } from '../types/processing';
 import { ProcessingCache } from './processingCache';
 import { pdfWorkerManager } from './pdfWorkerManager';
+import { createQuickKey } from '../types/fileContext';
 
 export class PDFProcessingService {
   private static instance: PDFProcessingService;
@@ -113,7 +114,7 @@ export class PDFProcessingService {
         const thumbnail = canvas.toDataURL();
 
         pages.push({
-          id: `${file.name}-page-${i}`,
+          id: `${createQuickKey(file)}-page-${i}`,
           pageNumber: i,
           thumbnail,
           rotation: 0,

frontend/src/tests/convert/ConvertIntegration.test.tsx

@@ -18,6 +18,8 @@ import { FileContextProvider } from '../../contexts/FileContext';
 import { I18nextProvider } from 'react-i18next';
 import i18n from '../../i18n/config';
 import axios from 'axios';
+import { createTestStirlingFile } from '../utils/testFileHelpers';
+import { StirlingFile } from '../../types/fileContext';
 
 // Mock axios
 vi.mock('axios');
@@ -55,9 +57,9 @@ const createTestFile = (name: string, content: string, type: string): File => {
   return new File([content], name, { type });
 };
 
-const createPDFFile = (): File => {
+const createPDFFile = (): StirlingFile => {
   const pdfContent = '%PDF-1.4\n1 0 obj\n<<\n/Type /Catalog\n/Pages 2 0 R\n>>\nendobj\ntrailer\n<<\n/Size 2\n/Root 1 0 R\n>>\nstartxref\n0\n%%EOF';
-  return createTestFile('test.pdf', pdfContent, 'application/pdf');
+  return createTestStirlingFile('test.pdf', pdfContent, 'application/pdf');
 };
 
 // Test wrapper component
@@ -162,7 +164,7 @@ describe('Convert Tool Integration Tests', () => {
         wrapper: TestWrapper
       });
 
-      const testFile = createTestFile('invalid.txt', 'not a pdf', 'text/plain');
+      const testFile = createTestStirlingFile('invalid.txt', 'not a pdf', 'text/plain');
       const parameters: ConvertParameters = {
         fromExtension: 'pdf',
         toExtension: 'png',
@@ -426,7 +428,7 @@ describe('Convert Tool Integration Tests', () => {
       });
       const files = [
         createPDFFile(),
-        createTestFile('test2.pdf', '%PDF-1.4...', 'application/pdf')
+        createTestStirlingFile('test2.pdf', '%PDF-1.4...', 'application/pdf')
       ]
       const parameters: ConvertParameters = {
         fromExtension: 'pdf',
@@ -527,7 +529,7 @@ describe('Convert Tool Integration Tests', () => {
         wrapper: TestWrapper
       });
 
-      const corruptedFile = createTestFile('corrupted.pdf', 'not-a-pdf', 'application/pdf');
+      const corruptedFile = createTestStirlingFile('corrupted.pdf', 'not-a-pdf', 'application/pdf');
       const parameters: ConvertParameters = {
         fromExtension: 'pdf',
         toExtension: 'png',

frontend/src/tests/convert/ConvertSmartDetectionIntegration.test.tsx

@@ -14,6 +14,8 @@ import i18n from '../../i18n/config';
 import axios from 'axios';
 import { detectFileExtension } from '../../utils/fileUtils';
 import { FIT_OPTIONS } from '../../constants/convertConstants';
+import { createTestStirlingFile, createTestFilesWithId } from '../utils/testFileHelpers';
+import { StirlingFile } from '../../types/fileContext';
 
 // Mock axios
 vi.mock('axios');
@@ -81,7 +83,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       });
 
       // Create mock DOCX file
-      const docxFile = new File(['docx content'], 'document.docx', { type: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document' });
+      const docxFile = createTestStirlingFile('document.docx', 'docx content', 'application/vnd.openxmlformats-officedocument.wordprocessingml.document');
 
       // Test auto-detection
       act(() => {
@@ -117,7 +119,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       });
 
       // Create mock unknown file
-      const unknownFile = new File(['unknown content'], 'document.xyz', { type: 'application/octet-stream' });
+      const unknownFile = createTestStirlingFile('document.xyz', 'unknown content', 'application/octet-stream');
 
       // Test auto-detection
       act(() => {
@@ -156,11 +158,11 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       });
 
       // Create mock image files
-      const imageFiles = [
+      const imageFiles = createTestFilesWithId([
-        new File(['jpg content'], 'photo1.jpg', { type: 'image/jpeg' }),
+        { name: 'photo1.jpg', content: 'jpg content', type: 'image/jpeg' },
-        new File(['png content'], 'photo2.png', { type: 'image/png' }),
+        { name: 'photo2.png', content: 'png content', type: 'image/png' },
-        new File(['gif content'], 'photo3.gif', { type: 'image/gif' })
+        { name: 'photo3.gif', content: 'gif content', type: 'image/gif' }
-      ];
+      ]);
 
       // Test smart detection for all images
       act(() => {
@@ -202,11 +204,11 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       });
 
       // Create mixed file types
-      const mixedFiles = [
+      const mixedFiles = createTestFilesWithId([
-        new File(['pdf content'], 'document.pdf', { type: 'application/pdf' }),
+        { name: 'document.pdf', content: 'pdf content', type: 'application/pdf' },
-        new File(['docx content'], 'spreadsheet.xlsx', { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' }),
+        { name: 'spreadsheet.xlsx', content: 'docx content', type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' },
-        new File(['pptx content'], 'presentation.pptx', { type: 'application/vnd.openxmlformats-officedocument.presentationml.presentation' })
+        { name: 'presentation.pptx', content: 'pptx content', type: 'application/vnd.openxmlformats-officedocument.presentationml.presentation' }
-      ];
+      ]);
 
       // Test smart detection for mixed types
       act(() => {
@@ -243,10 +245,10 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
       });
 
       // Create mock web files
-      const webFiles = [
+      const webFiles = createTestFilesWithId([
-        new File(['<html>content</html>'], 'page1.html', { type: 'text/html' }),
+        { name: 'page1.html', content: '<html>content</html>', type: 'text/html' },
-        new File(['zip content'], 'site.zip', { type: 'application/zip' })
+        { name: 'site.zip', content: 'zip content', type: 'application/zip' }
-      ];
+      ]);
 
       // Test smart detection for web files
       act(() => {
@@ -288,7 +290,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         wrapper: TestWrapper
       });
 
-      const htmlFile = new File(['<html>content</html>'], 'page.html', { type: 'text/html' });
+      const htmlFile = createTestStirlingFile('page.html', '<html>content</html>', 'text/html');
 
       // Set up HTML conversion parameters
       act(() => {
@@ -318,7 +320,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         wrapper: TestWrapper
       });
 
-      const emlFile = new File(['email content'], 'email.eml', { type: 'message/rfc822' });
+      const emlFile = createTestStirlingFile('email.eml', 'email content', 'message/rfc822');
 
       // Set up email conversion parameters
       act(() => {
@@ -355,7 +357,7 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         wrapper: TestWrapper
       });
 
-      const pdfFile = new File(['pdf content'], 'document.pdf', { type: 'application/pdf' });
+      const pdfFile = createTestStirlingFile('document.pdf', 'pdf content', 'application/pdf');
 
       // Set up PDF/A conversion parameters
       act(() => {
@@ -392,10 +394,10 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         wrapper: TestWrapper
       });
 
-      const imageFiles = [
+      const imageFiles = createTestFilesWithId([
-        new File(['jpg1'], 'photo1.jpg', { type: 'image/jpeg' }),
+        { name: 'photo1.jpg', content: 'jpg1', type: 'image/jpeg' },
-        new File(['jpg2'], 'photo2.jpg', { type: 'image/jpeg' })
+        { name: 'photo2.jpg', content: 'jpg2', type: 'image/jpeg' }
-      ];
+      ]);
 
       // Set up image conversion parameters
       act(() => {
@@ -432,10 +434,10 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         wrapper: TestWrapper
       });
 
-      const imageFiles = [
+      const imageFiles = createTestFilesWithId([
-        new File(['jpg1'], 'photo1.jpg', { type: 'image/jpeg' }),
+        { name: 'photo1.jpg', content: 'jpg1', type: 'image/jpeg' },
-        new File(['jpg2'], 'photo2.jpg', { type: 'image/jpeg' })
+        { name: 'photo2.jpg', content: 'jpg2', type: 'image/jpeg' }
-      ];
+      ]);
 
       // Set up for separate processing
       act(() => {
@@ -477,10 +479,10 @@ describe('Convert Tool - Smart Detection Integration Tests', () => {
         })
         .mockRejectedValueOnce(new Error('File 2 failed'));
 
-      const mixedFiles = [
+      const mixedFiles = createTestFilesWithId([
-        new File(['file1'], 'doc1.txt', { type: 'text/plain' }),
+        { name: 'doc1.txt', content: 'file1', type: 'text/plain' },
-        new File(['file2'], 'doc2.xyz', { type: 'application/octet-stream' })
+        { name: 'doc2.xyz', content: 'file2', type: 'application/octet-stream' }
-      ];
+      ]);
 
       // Set up for separate processing (mixed smart detection)
       act(() => {

frontend/src/tests/utils/testFileHelpers.ts

@@ -0,0 +1,28 @@
+/**
+ * Test utilities for creating StirlingFile objects in tests
+ */
+
+import { StirlingFile, createStirlingFile } from '../../types/fileContext';
+
+/**
+ * Create a StirlingFile object for testing purposes
+ */
+export function createTestStirlingFile(
+  name: string,
+  content: string = 'test content',
+  type: string = 'application/pdf'
+): StirlingFile {
+  const file = new File([content], name, { type });
+  return createStirlingFile(file);
+}
+
+/**
+ * Create multiple StirlingFile objects for testing
+ */
+export function createTestFilesWithId(
+  files: Array<{ name: string; content?: string; type?: string }>
+): StirlingFile[] {
+  return files.map(({ name, content = 'test content', type = 'application/pdf' }) =>
+    createTestStirlingFile(name, content, type)
+  );
+}

frontend/src/types/fileContext.ts

@@ -5,6 +5,9 @@
 import { PageOperation } from './pageEditor';
 import { FileId, FileMetadata } from './file';
 
+// Re-export FileId for convenience
+export type { FileId };
+
 export type ModeType =
   | 'viewer'
   | 'pageEditor'
@@ -42,25 +45,32 @@ export interface ProcessedFileMetadata {
   [key: string]: any;
 }
 
-export interface FileRecord {
+/**
-  id: FileId;
+ * StirlingFileStub - Metadata record for files in the active workbench session
-  name: string;
+ *
-  size: number;
+ * Contains UI display data and processing state. Actual File objects stored
-  type: string;
+ * separately in refs for memory efficiency. Supports multi-tool workflows
-  lastModified: number;
+ * where files persist across tool operations.
-  quickKey?: string; // Fast deduplication key: name|size|lastModified
+ */
-  thumbnailUrl?: string;
+export interface StirlingFileStub {
-  blobUrl?: string;
+  id: FileId;                    // UUID primary key for collision-free operations
-  createdAt?: number;
+  name: string;                  // Display name for UI
-  processedFile?: ProcessedFileMetadata;
+  size: number;                  // File size for progress indicators
-  insertAfterPageId?: string; // Page ID after which this file should be inserted
+  type: string;                  // MIME type for format validation
-  isPinned?: boolean;
+  lastModified: number;          // Original timestamp for deduplication
+  quickKey?: string;             // Fast deduplication key: name|size|lastModified
+  thumbnailUrl?: string;         // Generated thumbnail blob URL for visual display
+  blobUrl?: string;             // File access blob URL for downloads/processing
+  createdAt?: number;           // When added to workbench for sorting
+  processedFile?: ProcessedFileMetadata; // PDF page data and processing results
+  insertAfterPageId?: string;   // Page ID after which this file should be inserted
+  isPinned?: boolean;           // Protected from tool consumption (replace/remove)
   // Note: File object stored in provider ref, not in state
 }
 
 export interface FileContextNormalizedFiles {
   ids: FileId[];
-  byId: Record<FileId, FileRecord>;
+  byId: Record<FileId, StirlingFileStub>;
 }
 
 // Helper functions - UUID-based primary keys (zero collisions, synchronous)
@@ -83,9 +93,68 @@ export function createQuickKey(file: File): string {
   return `${file.name}|${file.size}|${file.lastModified}`;
 }
 
+// Stirling PDF file with embedded UUID - replaces loose File + FileId parameter passing
+export interface StirlingFile extends File {
+  readonly fileId: FileId;
+  readonly quickKey: string; // Fast deduplication key: name|size|lastModified
+}
+
+// Type guard to check if a File object has an embedded fileId
+export function isStirlingFile(file: File): file is StirlingFile {
+  return 'fileId' in file && typeof (file as any).fileId === 'string' &&
+         'quickKey' in file && typeof (file as any).quickKey === 'string';
+}
+
+// Create a StirlingFile from a regular File object
+export function createStirlingFile(file: File, id?: FileId): StirlingFile {
+  const fileId = id || createFileId();
+  const quickKey = createQuickKey(file);
+
+  // Use Object.defineProperty to add properties while preserving the original File object
+  // This maintains proper method binding and avoids "Illegal invocation" errors
+  Object.defineProperty(file, 'fileId', {
+    value: fileId,
+    writable: false,
+    enumerable: true,
+    configurable: false
+  });
+
+  Object.defineProperty(file, 'quickKey', {
+    value: quickKey,
+    writable: false,
+    enumerable: true,
+    configurable: false
+  });
+
+  return file as StirlingFile;
+}
+
+// Extract FileIds from StirlingFile array
+export function extractFileIds(files: StirlingFile[]): FileId[] {
+  return files.map(file => file.fileId);
+}
+
+// Extract regular File objects from StirlingFile array
+export function extractFiles(files: StirlingFile[]): File[] {
+  return files as File[];
+}
+
+// Check if an object is a File or StirlingFile (replaces instanceof File checks)
+export function isFileObject(obj: any): obj is File | StirlingFile {
+  return obj &&
+         typeof obj.name === 'string' &&
+         typeof obj.size === 'number' &&
+         typeof obj.type === 'string' &&
+         typeof obj.lastModified === 'number' &&
+         typeof obj.arrayBuffer === 'function';
+}
 
 
-export function toFileRecord(file: File, id?: FileId): FileRecord {
+
+export function toStirlingFileStub(
+  file: File,
+  id?: FileId
+): StirlingFileStub {
   const fileId = id || createFileId();
   return {
     id: fileId,
@@ -98,7 +167,7 @@ export function toFileRecord(file: File, id?: FileId): FileRecord {
   };
 }
 
-export function revokeFileResources(record: FileRecord): void {
+export function revokeFileResources(record: StirlingFileStub): void {
   // Only revoke blob: URLs to prevent errors on other schemes
   if (record.thumbnailUrl && record.thumbnailUrl.startsWith('blob:')) {
     try {
@@ -172,7 +241,7 @@ export interface FileContextState {
   // Core file management - lightweight file IDs only
   files: {
     ids: FileId[];
-    byId: Record<FileId, FileRecord>;
+    byId: Record<FileId, StirlingFileStub>;
   };
 
   // Pinned files - files that won't be consumed by tools
@@ -191,16 +260,16 @@ export interface FileContextState {
 // Action types for reducer pattern
 export type FileContextAction =
   // File management actions
-  | { type: 'ADD_FILES'; payload: { fileRecords: FileRecord[] } }
+  | { type: 'ADD_FILES'; payload: { stirlingFileStubs: StirlingFileStub[] } }
   | { type: 'REMOVE_FILES'; payload: { fileIds: FileId[] } }
-  | { type: 'UPDATE_FILE_RECORD'; payload: { id: FileId; updates: Partial<FileRecord> } }
+  | { type: 'UPDATE_FILE_RECORD'; payload: { id: FileId; updates: Partial<StirlingFileStub> } }
   | { type: 'REORDER_FILES'; payload: { orderedFileIds: FileId[] } }
 
   // Pinned files actions
   | { type: 'PIN_FILE'; payload: { fileId: FileId } }
   | { type: 'UNPIN_FILE'; payload: { fileId: FileId } }
-  | { type: 'CONSUME_FILES'; payload: { inputFileIds: FileId[]; outputFileRecords: FileRecord[] } }
+  | { type: 'CONSUME_FILES'; payload: { inputFileIds: FileId[]; outputStirlingFileStubs: StirlingFileStub[] } }
-  | { type: 'UNDO_CONSUME_FILES'; payload: { inputFileRecords: FileRecord[]; outputFileIds: FileId[] } }
+  | { type: 'UNDO_CONSUME_FILES'; payload: { inputStirlingFileStubs: StirlingFileStub[]; outputFileIds: FileId[] } }
 
   // UI actions
   | { type: 'SET_SELECTED_FILES'; payload: { fileIds: FileId[] } }
@@ -216,22 +285,22 @@ export type FileContextAction =
 
 export interface FileContextActions {
   // File management - lightweight actions only
-  addFiles: (files: File[], options?: { insertAfterPageId?: string; selectFiles?: boolean }) => Promise<File[]>;
+  addFiles: (files: File[], options?: { insertAfterPageId?: string; selectFiles?: boolean }) => Promise<StirlingFile[]>;
-  addProcessedFiles: (filesWithThumbnails: Array<{ file: File; thumbnail?: string; pageCount?: number }>) => Promise<File[]>;
+  addProcessedFiles: (filesWithThumbnails: Array<{ file: File; thumbnail?: string; pageCount?: number }>) => Promise<StirlingFile[]>;
-  addStoredFiles: (filesWithMetadata: Array<{ file: File; originalId: FileId; metadata: FileMetadata }>, options?: { selectFiles?: boolean }) => Promise<File[]>;
+  addStoredFiles: (filesWithMetadata: Array<{ file: File; originalId: FileId; metadata: FileMetadata }>, options?: { selectFiles?: boolean }) => Promise<StirlingFile[]>;
   removeFiles: (fileIds: FileId[], deleteFromStorage?: boolean) => Promise<void>;
-  updateFileRecord: (id: FileId, updates: Partial<FileRecord>) => void;
+  updateStirlingFileStub: (id: FileId, updates: Partial<StirlingFileStub>) => void;
   reorderFiles: (orderedFileIds: FileId[]) => void;
   clearAllFiles: () => Promise<void>;
   clearAllData: () => Promise<void>;
 
-  // File pinning
+  // File pinning - accepts StirlingFile for safer type checking
-  pinFile: (file: File) => void;
+  pinFile: (file: StirlingFile) => void;
-  unpinFile: (file: File) => void;
+  unpinFile: (file: StirlingFile) => void;
 
   // File consumption (replace unpinned files with outputs)
   consumeFiles: (inputFileIds: FileId[], outputFiles: File[]) => Promise<FileId[]>;
-  undoConsumeFiles: (inputFiles: File[], inputFileRecords: FileRecord[], outputFileIds: FileId[]) => Promise<void>;
+  undoConsumeFiles: (inputFiles: File[], inputStirlingFileStubs: StirlingFileStub[], outputFileIds: FileId[]) => Promise<void>;
   // Selection management
   setSelectedFiles: (fileIds: FileId[]) => void;
   setSelectedPages: (pageNumbers: number[]) => void;
@@ -254,26 +323,17 @@ export interface FileContextActions {
 
 // File selectors (separate from actions to avoid re-renders)
 export interface FileContextSelectors {
-  // File access - no state dependency, uses ref
+  getFile: (id: FileId) => StirlingFile | undefined;
-  getFile: (id: FileId) => File | undefined;
+  getFiles: (ids?: FileId[]) => StirlingFile[];
-  getFiles: (ids?: FileId[]) => File[];
+  getStirlingFileStub: (id: FileId) => StirlingFileStub | undefined;
-
+  getStirlingFileStubs: (ids?: FileId[]) => StirlingFileStub[];
-  // Record access - uses normalized state
-  getFileRecord: (id: FileId) => FileRecord | undefined;
-  getFileRecords: (ids?: FileId[]) => FileRecord[];
-
-  // Derived selectors
   getAllFileIds: () => FileId[];
-  getSelectedFiles: () => File[];
+  getSelectedFiles: () => StirlingFile[];
-  getSelectedFileRecords: () => FileRecord[];
+  getSelectedStirlingFileStubs: () => StirlingFileStub[];
-
-  // Pinned files selectors
   getPinnedFileIds: () => FileId[];
-  getPinnedFiles: () => File[];
+  getPinnedFiles: () => StirlingFile[];
-  getPinnedFileRecords: () => FileRecord[];
+  getPinnedStirlingFileStubs: () => StirlingFileStub[];
-  isFilePinned: (file: File) => boolean;
+  isFilePinned: (file: StirlingFile) => boolean;
-
-  // Stable signature for effect dependencies
   getFilesSignature: () => string;
 }
 
@@ -294,6 +354,3 @@ export interface FileContextActionsValue {
   actions: FileContextActions;
   dispatch: (action: FileContextAction) => void;
 }
-
-// TODO: URL parameter types will be redesigned for new routing system
-

frontend/src/types/fileIdSafety.d.ts

@@ -0,0 +1,49 @@
+/**
+ * Type safety declarations to prevent file.name/UUID confusion
+ */
+
+import { FileId, StirlingFile, OperationType, FileOperation } from './fileContext';
+
+declare global {
+  namespace FileIdSafety {
+    // Mark functions that should never accept file.name as parameters
+    type SafeFileIdFunction<T extends (...args: any[]) => any> = T extends (...args: infer P) => infer R
+      ? P extends readonly [string, ...any[]]
+        ? never // Reject string parameters in first position for FileId functions
+        : T
+      : T;
+
+    // Mark functions that should only accept StirlingFile, not regular File
+    type StirlingFileOnlyFunction<T extends (...args: any[]) => any> = T extends (...args: infer P) => infer R
+      ? P extends readonly [File, ...any[]]
+        ? never // Reject File parameters in first position for StirlingFile functions
+        : T
+      : T;
+
+    // Utility type to enforce StirlingFile usage
+    type RequireStirlingFile<T> = T extends File ? StirlingFile : T;
+  }
+
+  // Extend Window interface for debugging
+  interface Window {
+    __FILE_ID_DEBUG?: boolean;
+  }
+}
+
+// Augment FileContext types to prevent bypassing StirlingFile
+declare module '../contexts/FileContext' {
+  export interface StrictFileContextActions {
+    pinFile: (file: StirlingFile) => void; // Must be StirlingFile
+    unpinFile: (file: StirlingFile) => void; // Must be StirlingFile
+    addFiles: (files: File[], options?: { insertAfterPageId?: string }) => Promise<StirlingFile[]>; // Returns StirlingFile
+    consumeFiles: (inputFileIds: FileId[], outputFiles: File[]) => Promise<StirlingFile[]>; // Returns StirlingFile
+  }
+  
+  export interface StrictFileContextSelectors {
+    getFile: (id: FileId) => StirlingFile | undefined; // Returns StirlingFile
+    getFiles: (ids?: FileId[]) => StirlingFile[]; // Returns StirlingFile[]
+    isFilePinned: (file: StirlingFile) => boolean; // Must be StirlingFile
+  }
+}
+
+export {};

frontend/src/types/parameters.ts

@@ -1,7 +1,6 @@
 // Base parameter interfaces for reusable patterns
 
-export interface BaseParameters {
+// Base interface that all tool parameters should extend
-  // Base interface that all tool parameters should extend
+// Provides a foundation for adding common properties across all tools
-  // Provides a foundation for adding common properties across all tools
+// Examples of future additions: userId, sessionId, commonFlags, etc.
-  // Examples of future additions: userId, sessionId, commonFlags, etc.
+export type BaseParameters = object
-}

frontend/src/utils/fileIdSafety.ts

@@ -0,0 +1,14 @@
+/**
+ * Runtime validation utilities for FileId safety
+ */
+
+import { FileId } from '../types/fileContext';
+
+// Validate that a string is a proper FileId (has UUID format)
+export function isValidFileId(id: string): id is FileId {
+  // Check UUID v4 format: 8-4-4-4-12 hex digits
+  const uuidRegex = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+  return uuidRegex.test(id);
+}
+
+