chore: remove test files and clean up minor issues

- Delete src/test-dial.html and src/test-dial.tsx
- Remove trailing blank lines in background/index.ts
- Remove unused lastModified from File constructor in claude.tsx
- Remove eslint-disable comment in chatgpt.ts extractor

Author: vchan-in

src/background/index.ts

@@ -153,5 +153,3 @@ async function handleMessage(
       throw new Error(`Unknown message type: ${(message as any).type}`);
   }
 }
-
-

src/content-scripts/claude.tsx

@@ -20,7 +20,6 @@ function attachViaFileInput(text: string): boolean {
 
   const file = new File([text], "AI_Chat_Backup_Context_Seed.txt", {
     type: "text/plain",
-    lastModified: Date.now(),
   });
 
   const dt = new DataTransfer();

src/content-scripts/perplexity.tsx

@@ -146,7 +146,6 @@ export const chatgptExtractor: Extractor = {
     let offset = 0;
     const limit = 100;
 
-    // eslint-disable-next-line no-constant-condition
     while (true) {
       const page = await apiFetch<RawConvList>(
         `/conversations?offset=${offset}&limit=${limit}&order=updated`