test: add comprehensive AI feature install/uninstall test coverage

- Add 55 unit tests for feature-status.ts (installed.json CRUD, cache
  behavior, install lock, model verification, crash recovery, composite
  state) using real temp directories
- Add 36 integration tests for full install/uninstall lifecycle against
  Docker containers (face-detection bundle, SSE progress, tool gates,
  shared model protection, concurrent install prevention, auth guards,
  container restart recovery)
- Fix noise-removal CPU timeout by adding megapixel-based timeout
  calculation (120s/MP, min 5 minutes)
- Fix Playwright auth storage state race condition (mkdirSync before
  saving analytics-user.json)
- Fix 2 skipped tests in fixes-verification.spec.ts by replacing
  external ~/Downloads/sample dependency with existing test fixtures
- Enable skipped analytics-consent settings toggle test
- Restructure features.spec.ts to manage bundle state (uninstall/
  reinstall OCR) so 501 guard tests run instead of skipping
- Update noise-removal test mock to include sharp metadata() method

packages/ai/src/noise-removal.ts

@@ -31,10 +31,15 @@ export async function noiseRemoval(
 
   const pngBuffer = await sharp(inputBuffer).png().toBuffer();
   await writeFile(inputPath, pngBuffer);
+
+  const meta = await sharp(pngBuffer).metadata();
+  const megapixels = ((meta.width ?? 0) * (meta.height ?? 0)) / 1_000_000;
+  const timeout = Math.max(300_000, megapixels * 120_000);
+
   const { stdout } = await runPythonWithProgress(
     "noise_removal.py",
     [inputPath, outputPath, JSON.stringify(options)],
-    { onProgress },
+    { onProgress, timeout },
   );
 
   const result = parseStdoutJson(stdout);