add .env init tests

[ian]

Summary by cubic

Automatically creates or updates .env.local during CLI init to ensure required env vars (AUTH_SECRET, DATABASE_URL) are present. Addresses Linear STARTUP-123 by automating .env.local setup after install.

• New Features
  • CLI init now writes or merges .env.local with required keys, preserves comments, and logs added vars.
  • Added helpers (parseEnvKeys, generateEnvContent, mergeEnvContent) with unit tests for parsing, generation, and merging behavior.

^{Written for commit b94a32e. Summary will update on new commits.}

[linear]

STARTUP-123 Automatically `cp .env.example .env.local`after install

[cloudflare-workers-and-pages]

Deploying startupkit with    Cloudflare Pages

Latest commit:	b94a32e
Status:	✅  Deploy successful!
Preview URL:	https://05e43332.startupkit-975.pages.dev
Branch Preview URL:	https://ian-startup-123-automaticall.startupkit-975.pages.dev

View logs

[cubic-dev-ai]

No issues found across 2 files