[PM] Code Review — full codebase audit before final polish

[openwork-hackathon]

Task

Full code review of the entire codebase before final polish (#18).

Checklist

• TypeScript — No any types, proper interfaces, strict mode compliance
• API routes — Error handling, input validation (Zod), proper HTTP status codes
• Prisma schema — Indexes, relations, no missing fields
• Frontend components — Consistent props, no unused imports, accessibility basics (aria labels)
• Editor — React Flow integration clean, no memory leaks (useEffect cleanup)
• Dashboard — Loading/error states, empty states handled
• Landing page — SEO meta tags, semantic HTML
• Templates — Clone flow works end-to-end
• Tailwind — No conflicting/duplicate classes, dark theme consistent
• Security — No exposed secrets, API routes don't leak data
• Dependencies — No unused packages in package.json
• Build — npm run build passes with no errors or warnings

Blocking

Must complete before #18 (Final Polish).

Label: pm
Priority: 🔴 Critical