Enforce type checking in CI (#4126)

# Description of Changes
Currently, the `tsconfig.json` file enforces strict type checking, but
nothing in CI checks that the code is actually correctly typed. [Vite
only transpiles TypeScript
code](https://vite.dev/guide/features.html#transpile-only) so doesn't
ensure that the TS code we're running is correct.

This PR adds running of the type checker to CI and fixes the type errors
that have already crept into the codebase.

Note that many of the changes I've made to 'fix the types' are just
using `any` to disable the type checker because the code is under too
much churn to fix anything properly at the moment. I still think
enabling the type checker now is the best course of action though
because otherwise we'll never be able to fix all of them, and it should
at least help us not break things when adding new code.

Co-authored-by: James <[email protected]>

frontend/src/services/pdfProcessingService.ts

@@ -22,20 +22,20 @@ export class PDFProcessingService {
 
   async getProcessedFile(file: File): Promise<ProcessedFile | null> {
     const fileKey = this.generateFileKey(file);
-    
+
     // Check cache first
     const cached = this.cache.get(fileKey);
     if (cached) {
       console.log('Cache hit for:', file.name);
       return cached;
     }
-    
+
     // Check if already processing
     if (this.processing.has(fileKey)) {
       console.log('Already processing:', file.name);
       return null; // Will be available when processing completes
     }
-    
+
     // Start processing
     this.startProcessing(file, fileKey);
     return null;
@@ -48,9 +48,10 @@ export class PDFProcessingService {
       fileName: file.name,
       status: 'processing',
       progress: 0,
-      startedAt: Date.now()
+      startedAt: Date.now(),
+      strategy: 'immediate_full'
     };
-    
+
     this.processing.set(fileKey, state);
     this.notifyListeners();
 
@@ -63,13 +64,13 @@ export class PDFProcessingService {
 
       // Cache the result
       this.cache.set(fileKey, processedFile);
-      
+
       // Update state to completed
       state.status = 'completed';
       state.progress = 100;
       state.completedAt = Date.now();
       this.notifyListeners();
-      
+
       // Remove from processing map after brief delay
       setTimeout(() => {
         this.processing.delete(fileKey);
@@ -79,9 +80,9 @@ export class PDFProcessingService {
     } catch (error) {
       console.error('Processing failed for', file.name, ':', error);
       state.status = 'error';
-      state.error = error instanceof Error ? error.message : 'Unknown error';
+      state.error = (error instanceof Error ? error.message : 'Unknown error') as any;
       this.notifyListeners();
-      
+
       // Remove failed processing after delay
       setTimeout(() => {
         this.processing.delete(fileKey);
@@ -91,29 +92,29 @@ export class PDFProcessingService {
   }
 
   private async processFileWithProgress(
-    file: File, 
+    file: File,
     onProgress: (progress: number) => void
   ): Promise<ProcessedFile> {
     const arrayBuffer = await file.arrayBuffer();
     const pdf = await getDocument({ data: arrayBuffer }).promise;
     const totalPages = pdf.numPages;
-    
+
     onProgress(10); // PDF loaded
-    
+
     const pages: PDFPage[] = [];
-    
+
     for (let i = 1; i <= totalPages; i++) {
       const page = await pdf.getPage(i);
       const viewport = page.getViewport({ scale: 0.5 });
       const canvas = document.createElement('canvas');
       canvas.width = viewport.width;
       canvas.height = viewport.height;
-      
+
       const context = canvas.getContext('2d');
       if (context) {
         await page.render({ canvasContext: context, viewport }).promise;
         const thumbnail = canvas.toDataURL();
-        
+
         pages.push({
           id: `${file.name}-page-${i}`,
           pageNumber: i,
@@ -122,15 +123,15 @@ export class PDFProcessingService {
           selected: false
         });
       }
-      
+
       // Update progress
       const progress = 10 + (i / totalPages) * 85; // 10-95%
       onProgress(progress);
     }
-    
+
     pdf.destroy();
     onProgress(100);
-    
+
     return {
       id: `${Date.now()}-${Math.random().toString(36).substr(2, 9)}`,
       pages,
@@ -185,4 +186,4 @@ export class PDFProcessingService {
 }
 
 // Export singleton instance
-export const pdfProcessingService = PDFProcessingService.getInstance();
+export const pdfProcessingService = PDFProcessingService.getInstance();