fix(P0-001): add missing typescript-eslint dep, format all files

Add typescript-eslint to root devDependencies (required by eslint
flat config). Run prettier across all files. Exclude QA reports
from git.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -8,3 +8,4 @@ coverage
 .env.local
 *.tsbuildinfo
 .pnpm-store
+docs/reports/