Fix filewithid use

frontend/.eslintrc.js

@@ -0,0 +1,55 @@
+module.exports = {
+  extends: [
+    'react-app',
+    'react-app/jest'
+  ],
+  rules: {
+    // Custom rules to prevent dangerous file.name as ID patterns
+    'no-file-name-as-id': 'error',
+    'prefer-file-with-id': 'warn'
+  },
+  overrides: [
+    {
+      files: ['**/*.ts', '**/*.tsx'],
+      rules: {
+        // Prevent file.name being used where FileId is expected
+        'no-restricted-syntax': [
+          'error',
+          {
+            selector: 'MemberExpression[object.name="file"][property.name="name"]',
+            message: 'Avoid using file.name directly. Use FileWithId.fileId or safeGetFileId() instead to prevent ID collisions.'
+          },
+          {
+            selector: 'CallExpression[callee.name="createOperation"] > ArrayExpression > CallExpression[callee.property.name="map"] > ArrowFunctionExpression > MemberExpression[object.name="f"][property.name="name"]',
+            message: 'Dangerous pattern: Using file.name as ID in createOperation. Use FileWithId.fileId instead.'
+          },
+          {
+            selector: 'ArrayExpression[elements.length>0] CallExpression[callee.property.name="map"] > ArrowFunctionExpression > MemberExpression[property.name="name"]',
+            message: 'Potential file.name as ID usage detected. Ensure proper FileId usage instead of file.name.'
+          }
+        ]
+      }
+    }
+  ],
+  settings: {
+    // Custom settings for our file ID validation
+    'file-id-validation': {
+      // Functions that should only accept FileId, not strings
+      'file-id-only-functions': [
+        'recordOperation',
+        'markOperationApplied', 
+        'markOperationFailed',
+        'removeFiles',
+        'updateFileRecord',
+        'pinFile',
+        'unpinFile'
+      ],
+      // Functions that should accept FileWithId instead of File
+      'file-with-id-functions': [
+        'createOperation',
+        'executeOperation',
+        'isFilePinned'
+      ]
+    }
+  }
+};

frontend/src/App.tsx

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

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, FileWithId } from '../../types/fileContext';
 
 
 interface FileEditorProps {
-  onOpenPageEditor?: (file: File) => void;
-  onMergeFiles?: (files: File[]) => void;
+  onOpenPageEditor?: (file: FileWithId) => void;
+  onMergeFiles?: (files: FileWithId[]) => void;
   toolMode?: boolean;
   showUpload?: boolean;
   showBulkActions?: boolean;
@@ -421,7 +421,7 @@ const FileEditor = ({
     if (startIndex === -1) return;
 
     const recordsToMerge = activeFileRecords.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 FileWithId[];
     if (onMergeFiles) {
       onMergeFiles(filesToMerge);
     }

frontend/src/components/shared/FileCard.tsx

@@ -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

@@ -124,8 +124,12 @@ const FileGrid = ({
         style={{ overflowY: "auto", width: "100%" }}
       >
         {displayFiles.map((item, idx) => {
-          const fileId = item.record?.id || item.file.name as FileId /* FIX ME: This doesn't seem right */;
-          const originalIdx = files.findIndex(f => (f.record?.id || f.file.name) === fileId);
+          if (!item.record?.id) {
+            console.error('FileGrid: File missing FileRecord with proper ID:', item.file.name);
+            return null;
+          }
+          const fileId = item.record.id;
+          const originalIdx = files.findIndex(f => f.record?.id === fileId);
           const supported = isFileSupported ? isFileSupported(item.file.name) : true;
           return (
             <FileCard

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 { FileWithId } 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: FileWithId[];
   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 FileWithId[];
     return files.filter(file => {
       const fileExtension = detectFileExtension(file.name);
 
@@ -143,21 +143,8 @@ const ConvertSettings = ({
     });
   };
 
-  const updateFileSelection = (files: File[]) => {
-    // Map File objects to their actual IDs in FileContext
-    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
-
+  const updateFileSelection = (files: FileWithId[]) => {
+    const fileIds = files.map(file => file.fileId);
     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 { FileWithId } from '../../../types/fileContext';
 
 interface ConvertToPdfaSettingsProps {
   parameters: ConvertParameters;
   onParameterChange: (key: keyof ConvertParameters, value: any) => void;
-  selectedFiles: File[];
+  selectedFiles: FileWithId[];
   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 { FileWithId } from "../../../types/fileContext";
 
 export interface FileStatusIndicatorProps {
-  selectedFiles?: File[];
+  selectedFiles?: FileWithId[];
   placeholder?: string;
 }
 

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 { FileWithId } from '../../../types/fileContext';
 
 export interface FilesToolStepProps {
-  selectedFiles: File[];
+  selectedFiles: FileWithId[];
   isCollapsed?: boolean;
   onCollapsedClick?: () => void;
   placeholder?: string;

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 { FileWithId } from '../../../types/fileContext';
 
 export interface FilesStepConfig {
-  selectedFiles: File[];
+  selectedFiles: FileWithId[];
   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/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 { FileWithId } from '../../../types/fileContext';
 
 interface BaseToolReturn<TParams> {
   // File management
-  selectedFiles: File[];
+  selectedFiles: FileWithId[];
 
   // Tool-specific hooks
   params: BaseParametersHook<TParams>;

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
-    if (!(file instanceof File) && !(file instanceof Blob)) {
+    // Validate that file is a proper File, FileWithId, or Blob object
+    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/usePdfSignatureDetection.ts

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

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 { createTestFileWithId, createTestFilesWithId } from '../utils/testFileHelpers';
+import { FileWithId } 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 = createTestFileWithId('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 = createTestFileWithId('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 = [
-        new File(['jpg content'], 'photo1.jpg', { type: 'image/jpeg' }),
-        new File(['png content'], 'photo2.png', { type: 'image/png' }),
-        new File(['gif content'], 'photo3.gif', { type: 'image/gif' })
-      ];
+      const imageFiles = createTestFilesWithId([
+        { name: 'photo1.jpg', content: 'jpg content', type: 'image/jpeg' },
+        { name: 'photo2.png', content: 'png content', type: 'image/png' },
+        { 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 = [
-        new File(['pdf content'], 'document.pdf', { type: 'application/pdf' }),
-        new File(['docx content'], 'spreadsheet.xlsx', { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' }),
-        new File(['pptx content'], 'presentation.pptx', { type: 'application/vnd.openxmlformats-officedocument.presentationml.presentation' })
-      ];
+      const mixedFiles = createTestFilesWithId([
+        { name: 'document.pdf', content: 'pdf content', type: 'application/pdf' },
+        { name: 'spreadsheet.xlsx', content: 'docx content', type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' },
+        { 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 = [
-        new File(['<html>content</html>'], 'page1.html', { type: 'text/html' }),
-        new File(['zip content'], 'site.zip', { type: 'application/zip' })
-      ];
+      const webFiles = createTestFilesWithId([
+        { name: 'page1.html', content: '<html>content</html>', type: 'text/html' },
+        { 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 = createTestFileWithId('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 = createTestFileWithId('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 = createTestFileWithId('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 = [
-        new File(['jpg1'], 'photo1.jpg', { type: 'image/jpeg' }),
-        new File(['jpg2'], 'photo2.jpg', { type: 'image/jpeg' })
-      ];
+      const imageFiles = createTestFilesWithId([
+        { name: 'photo1.jpg', content: 'jpg1', 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 = [
-        new File(['jpg1'], 'photo1.jpg', { type: 'image/jpeg' }),
-        new File(['jpg2'], 'photo2.jpg', { type: 'image/jpeg' })
-      ];
+      const imageFiles = createTestFilesWithId([
+        { name: 'photo1.jpg', content: 'jpg1', 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 = [
-        new File(['file1'], 'doc1.txt', { type: 'text/plain' }),
-        new File(['file2'], 'doc2.xyz', { type: 'application/octet-stream' })
-      ];
+      const mixedFiles = createTestFilesWithId([
+        { name: 'doc1.txt', content: 'file1', type: 'text/plain' },
+        { name: 'doc2.xyz', content: 'file2', type: 'application/octet-stream' }
+      ]);
 
       // Set up for separate processing (mixed smart detection)
       act(() => {

frontend/src/types/fileIdSafety.d.ts

@@ -0,0 +1,50 @@
+/**
+ * Type safety declarations to prevent file.name/UUID confusion
+ */
+
+import { FileId, FileWithId, 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 FileWithId, not regular File
+    type FileWithIdOnlyFunction<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 FileWithId functions
+        : T
+      : T;
+
+    // Utility type to enforce FileWithId usage
+    type RequireFileWithId<T> = T extends File ? FileWithId : T;
+  }
+
+  // Extend Window interface to add runtime validation helpers
+  interface Window {
+    __FILE_ID_DEBUG?: boolean;
+    __validateFileId?: (id: string, context: string) => void;
+  }
+}
+
+// Augment FileContext types to prevent bypassing FileWithId
+declare module '../contexts/FileContext' {
+  export interface StrictFileContextActions {
+    pinFile: (file: FileWithId) => void; // Must be FileWithId
+    unpinFile: (file: FileWithId) => void; // Must be FileWithId
+    addFiles: (files: File[], options?: { insertAfterPageId?: string }) => Promise<FileWithId[]>; // Returns FileWithId
+    consumeFiles: (inputFileIds: FileId[], outputFiles: File[]) => Promise<FileWithId[]>; // Returns FileWithId
+  }
+  
+  export interface StrictFileContextSelectors {
+    getFile: (id: FileId) => FileWithId | undefined; // Returns FileWithId
+    getFiles: (ids?: FileId[]) => FileWithId[]; // Returns FileWithId[]
+    isFilePinned: (file: FileWithId) => boolean; // Must be FileWithId
+  }
+}
+
+export {};

frontend/src/utils/fileIdSafety.ts

@@ -0,0 +1,79 @@
+/**
+ * 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}$/i;
+  return uuidRegex.test(id);
+}
+
+// Detect potentially dangerous file.name usage as ID
+export function isDangerousFileNameAsId(fileName: string, context: string = ''): boolean {
+  // Check if it's definitely a UUID (safe)
+  if (isValidFileId(fileName)) {
+    return false;
+  }
+  
+  // Check if it's a quickKey (safe) - format: name|size|lastModified
+  if (/^.+\|\d+\|\d+$/.test(fileName)) {
+    return false; // quickKeys are legitimate, not dangerous
+  }
+  
+  // Common patterns that suggest file.name is being used as ID
+  const dangerousPatterns = [
+    /^[^-]+-page-\d+$/, // pattern: filename-page-123
+    /\.(pdf|jpg|png|doc|docx)$/i, // ends with file extension
+    /\s/, // contains whitespace (filenames often have spaces)
+    /[()[\]{}]/, // contains brackets/parentheses common in filenames
+    /['"]/, // contains quotes
+    /[^a-zA-Z0-9\-._]/ // contains special characters not in UUIDs
+  ];
+  
+  // Check dangerous patterns
+  const isDangerous = dangerousPatterns.some(pattern => pattern.test(fileName));
+  
+  if (isDangerous && context) {
+    console.warn(`⚠️ Potentially dangerous file.name usage detected in ${context}: "${fileName}"`);
+  }
+  
+  return isDangerous;
+}
+
+// Runtime validation for FileId usage in development
+export function validateFileId(id: string, context: string): void {
+  if (process.env.NODE_ENV === 'development') {
+    // Check if it looks like a dangerous file.name usage
+    if (isDangerousFileNameAsId(id, context)) {
+      console.error(`💀 DANGEROUS: file.name used as FileId in ${context}! This will cause ID collisions.`);
+      console.trace('Stack trace:');
+    }
+  }
+}
+
+// Runtime validation for File vs FileWithId usage
+export function validateFileWithId(file: File, context: string): void {
+  // Check if file has embedded fileId
+  if (!('fileId' in file)) {
+    console.warn(`⚠️ Regular File object used where FileWithId expected in ${context}: "${file.name}"`);
+    console.warn('Consider using FileWithId for better type safety');
+  }
+}
+
+// Assertion for FileId validation (throws in development)
+export function assertValidFileId(id: string, context: string): void {
+  if (process.env.NODE_ENV === 'development') {
+    if (isDangerousFileNameAsId(id, context)) {
+      throw new Error(`ASSERTION FAILED: Dangerous file.name as FileId detected in ${context}: "${id}"`);
+    }
+  }
+}
+
+// Global debug helpers (can be enabled in dev tools)
+if (typeof window !== 'undefined') {
+  window.__FILE_ID_DEBUG = process.env.NODE_ENV === 'development';
+  window.__validateFileId = validateFileId;
+}