Local packaging (go build + flutter build macos)

[enegalan]

Summary

Document and verify local build steps for the daemon and macOS UI.

Tasks

• Add build instructions to DEVELOPMENT.md
• Verify go build -o calf ./cmd/calf from backend/
• Verify flutter build macos from ui/
• Define where binaries/artifacts are output
• Optionally add a Makefile or scripts/build.sh to run both builds

Acceptance criteria

• Daemon binary builds without errors on macOS
• macOS app bundle builds without errors
• Built app connects to a running daemon and shows status

Parent

Part of #1