chore: update dependencies and remove placeholder tests

[mldangelo]

Summary

• Update all dependencies to latest compatible versions
• Standardize Node.js version requirement to >=22 across all packages
• Fix server tsconfig for proper ESM module resolution
• Remove 9 placeholder test files that only contained expect(true).toBe(true)
• Rewrite integration tests with meaningful assertions

Changes

Dependencies

• React 19.2.0 → 19.2.1
• Express 5.0.1 → 5.2.1
• Vite 7.2.2 → 7.2.6
• Vitest 4.0.7 → 4.0.15 (fixed mismatch with @vitest/ui)
• Plus other minor version updates

Configuration Fixes

• Fixed Node.js engine inconsistency (root: >=22, workspaces were >=20)
• Fixed server tsconfig module: CommonJS conflicting with type: module in package.json
• Changed to module: ESNext with moduleResolution: bundler for tsx compatibility

Test Cleanup

Removed placeholder tests that gave false confidence:

• app/src/components/EvaluationDropdown.test.tsx
• app/src/components/ResultsTable.test.tsx
• app/src/hooks/useEvaluations.test.ts
• app/src/utils/api.test.ts
• server/src/index.test.ts
• server/src/db.test.ts
• server/src/models/eval.test.ts
• e2e/app.e2e.test.ts

Rewrote App.integration.test.tsx with 7 real tests that actually verify behavior.

Test plan

• All frontend tests pass (9 tests)
• Frontend builds successfully
• Server TypeScript compiles without errors
• ESLint passes
• Prettier formatting verified
• Manual E2E verification (started app, curled API, verified responses)