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/hooks/tools/shared/useToolApiCalls.ts

@@ -1,7 +1,7 @@
 import { useCallback, useRef } from 'react';
 import axios, { CancelTokenSource } from 'axios';
-import { processResponse } from '../../../utils/toolResponseProcessor';
-import type { ResponseHandler, ProcessingProgress } from './useToolState';
+import { processResponse, ResponseHandler } from '../../../utils/toolResponseProcessor';
+import type { ProcessingProgress } from './useToolState';
 
 export interface ApiCallsConfig<TParams = void> {
   endpoint: string | ((params: TParams) => string);

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

@@ -7,7 +7,7 @@ import { useToolApiCalls, type ApiCallsConfig } from './useToolApiCalls';
 import { useToolResources } from './useToolResources';
 import { extractErrorMessage } from '../../../utils/toolErrorHandler';
 import { createOperation } from '../../../utils/toolOperationTracker';
-import { type ResponseHandler, processResponse } from '../../../utils/toolResponseProcessor';
+import { ResponseHandler } from '../../../utils/toolResponseProcessor';
 
 export interface ValidationResult {
   valid: boolean;
@@ -176,7 +176,7 @@ export const useToolOperation = <TParams = void>(
           } else {
             // Default: assume ZIP response for multi-file endpoints
             processedFiles = await extractZipFiles(response.data);
-            
+
             if (processedFiles.length === 0) {
               // Try the generic extraction as fallback
               processedFiles = await extractAllZipFiles(response.data);
@@ -186,7 +186,7 @@ export const useToolOperation = <TParams = void>(
           // Individual file processing - separate API call per file
           const apiCallsConfig: ApiCallsConfig<TParams> = {
             endpoint: config.endpoint,
-            buildFormData: (file: File, params: TParams) => (config.buildFormData as (file: File, params: TParams) => FormData)(file, params),
+            buildFormData: (file: File, params: TParams) => (config.buildFormData as any /* FIX ME */)(file, params),
             filePrefix: config.filePrefix,
             responseHandler: config.responseHandler
           };

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

@@ -36,17 +36,19 @@ export const useToolResources = () => {
 
   const generateThumbnails = useCallback(async (files: File[]): Promise<string[]> => {
     const thumbnails: string[] = [];
-    
+
     for (const file of files) {
       try {
         const thumbnail = await generateThumbnailForFile(file);
-        thumbnails.push(thumbnail);
+        if (thumbnail) {
+          thumbnails.push(thumbnail);
+        }
       } catch (error) {
         console.warn(`Failed to generate thumbnail for ${file.name}:`, error);
         thumbnails.push('');
       }
     }
-    
+
     return thumbnails;
   }, []);
 
@@ -65,12 +67,12 @@ export const useToolResources = () => {
     try {
       const JSZip = (await import('jszip')).default;
       const zip = new JSZip();
-      
+
       const arrayBuffer = await zipBlob.arrayBuffer();
       const zipContent = await zip.loadAsync(arrayBuffer);
-      
+
       const extractedFiles: File[] = [];
-      
+
       for (const [filename, file] of Object.entries(zipContent.files)) {
         if (!file.dir) {
           const content = await file.async('blob');
@@ -78,7 +80,7 @@ export const useToolResources = () => {
           extractedFiles.push(extractedFile);
         }
       }
-      
+
       return extractedFiles;
     } catch (error) {
       console.error('Error in extractAllZipFiles:', error);
@@ -87,7 +89,7 @@ export const useToolResources = () => {
   }, []);
 
   const createDownloadInfo = useCallback(async (
-    files: File[], 
+    files: File[],
     operationType: string
   ): Promise<{ url: string; filename: string }> => {
     if (files.length === 1) {
@@ -100,7 +102,7 @@ export const useToolResources = () => {
     const { zipFile } = await zipFileService.createZipFromFiles(files, `${operationType}_results.zip`);
     const url = URL.createObjectURL(zipFile);
     addBlobUrl(url);
-    
+
     return { url, filename: zipFile.name };
   }, [addBlobUrl]);
 
@@ -111,4 +113,4 @@ export const useToolResources = () => {
     extractAllZipFiles,
     cleanupBlobUrls,
   };
-};
+};