chore: add pre-commit hooks, tighten ESLint, activate Sentry DSN, publish CI coverage (Phase 1)

- Install husky v9 + lint-staged: pre-commit runs eslint --fix and prettier on staged files
- Tighten ESLint base config: no-console→error, ban-ts-comment (ts-ignore banned, ts-expect-error with description allowed), reportUnusedDisableDirectives→error
- Migrate web app from deprecated `next lint` to `eslint src/` with flat config and react-hooks plugin
- Convert all 5 @ts-ignore to @ts-expect-error with descriptions, remove stale disable comments
- Add NEXT_PUBLIC_SENTRY_DSN to docker-compose.prod.yml and .env.example
- Add coverage artifact upload step to CI test job
- Pre-existing violations (102 warnings) downgraded to warn in web config for Phase 2 cleanup

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

apps/web/package.json

@@ -6,7 +6,7 @@
     "dev": "next dev -p 3100",
     "build": "next build",
     "start": "next start -p 3100",
-    "lint": "next lint",
+    "lint": "eslint src/",
     "typecheck": "tsc --project tsconfig.typecheck.json --noEmit",
     "test:unit": "vitest run",
     "test:e2e": "playwright test",
@@ -49,6 +49,7 @@
     "zod": "^3.23.8"
   },
   "devDependencies": {
+    "@capakraken/eslint-config": "workspace:*",
     "@capakraken/tsconfig": "workspace:*",
     "@playwright/test": "^1.49.1",
     "@types/dompurify": "^3.2.0",
@@ -59,6 +60,7 @@
     "@types/three": "^0.183.1",
     "@vitest/coverage-v8": "^2.1.9",
     "autoprefixer": "^10.4.20",
+    "eslint": "^10.2.0",
     "postcss": "^8.4.49",
     "tailwindcss": "^3.4.17",
     "typescript": "^5.6.3",