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/fileAnalyzer.ts

@@ -36,11 +36,11 @@ export class FileAnalyzer {
 
       // Determine strategy based on file characteristics
       analysis.recommendedStrategy = this.determineStrategy(file.size, quickAnalysis.pageCount);
-      
+
       // Estimate processing time
       analysis.estimatedProcessingTime = this.estimateProcessingTime(
-        file.size, 
-        quickAnalysis.pageCount, 
+        file.size,
+        quickAnalysis.pageCount,
         analysis.recommendedStrategy
       );
 
@@ -66,15 +66,15 @@ export class FileAnalyzer {
       // For large files, try the whole file first (PDF.js needs the complete structure)
       const arrayBuffer = await file.arrayBuffer();
 
-      const pdf = await getDocument({ 
+      const pdf = await getDocument({
         data: arrayBuffer,
         stopAtErrors: false, // Don't stop at minor errors
         verbosity: 0 // Suppress PDF.js warnings
       }).promise;
 
       const pageCount = pdf.numPages;
-      const isEncrypted = pdf.isEncrypted;
-      
+      const isEncrypted = (pdf as any).isEncrypted;
+
       // Clean up
       pdf.destroy();
 
@@ -88,7 +88,7 @@ export class FileAnalyzer {
       // Try to determine if it's corruption vs encryption
       const errorMessage = error instanceof Error ? error.message.toLowerCase() : '';
       const isEncrypted = errorMessage.includes('password') || errorMessage.includes('encrypted');
-      
+
       return {
         pageCount: 0,
         isEncrypted,
@@ -129,8 +129,8 @@ export class FileAnalyzer {
    * Estimate processing time based on file characteristics and strategy
    */
   private static estimateProcessingTime(
-    fileSize: number, 
-    pageCount: number = 0, 
+    fileSize: number,
+    pageCount: number = 0,
     strategy: ProcessingStrategy
   ): number {
     const baseTimes = {
@@ -145,20 +145,20 @@ export class FileAnalyzer {
     switch (strategy) {
       case 'metadata_only':
         return baseTime;
-      
+
       case 'immediate_full':
         return pageCount * baseTime;
-      
+
       case 'priority_pages':
         // Estimate time for priority pages (first 10)
         const priorityPages = Math.min(pageCount, 10);
         return priorityPages * baseTime;
-      
+
       case 'progressive_chunked':
         // Estimate time for first chunk (20 pages)
         const firstChunk = Math.min(pageCount, 20);
         return firstChunk * baseTime;
-      
+
       default:
         return pageCount * baseTime;
     }
@@ -209,11 +209,11 @@ export class FileAnalyzer {
     if (totalSize > this.SIZE_THRESHOLDS.LARGE) {
       return Math.max(1, Math.floor(fileCount / 4));
     }
-    
+
     if (totalSize > this.SIZE_THRESHOLDS.MEDIUM) {
       return Math.max(2, Math.floor(fileCount / 2));
     }
-    
+
     // Process all at once for smaller total sizes
     return fileCount;
   }
@@ -231,10 +231,10 @@ export class FileAnalyzer {
       const header = file.slice(0, 8);
       const headerBytes = new Uint8Array(await header.arrayBuffer());
       const headerString = String.fromCharCode(...headerBytes);
-      
+
       return headerString.startsWith('%PDF-');
     } catch (error) {
       return false;
     }
   }
-}
+}