Add Cursor Cloud development environment setup instructions

[vitaliimelnychuk]

Summary

Adds Cursor Cloud specific development environment instructions to AGENTS.md so future cloud agents can quickly set up and run the Cerberus app.

Changes

• Added ## Cursor Cloud specific instructions section to AGENTS.md covering:
  • PostgreSQL setup details (local PG 16, database/user/password)
  • Environment file gotcha: Prisma CLI needs .env (not just .env.local) because prisma.config.ts imports dotenv/config
  • Dev server and route protection notes
  • Pre-commit hook documentation

Development Environment Verification

All checks pass:

• Lint (npm run lint): clean
• Typecheck (npm run typecheck): clean
• Tests (npm run test): 18/18 passing across 3 test files
• Build (npm run build): successful production build
• Dev server (npm run dev): running on port 3000, pages render correctly

Demo

cerberus_app_demo.mp4

Login page renders with Cerberus branding, Google OAuth flow is wired up, and protected routes redirect properly.

Cerberus login page
Google OAuth flow initiated

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