P2: Service-aware upgrade coordination (stop/start service safely)

[Kinin-Code-Offical]

[Kinin-Code-Offical]

Plan

• Make install and update service-aware:
  • If the Windows Service (cloudsql-proxy) is installed and running, stop it before replacing the proxy binary, then restart it after a successful install/update.
  • If stopping/starting requires Admin and we’re not elevated, fail fast with a clear message.
• Harden proxy download/write:
  • Download to a temp file, verify checksum, then atomically replace the target exe (avoid partial writes).

Risks

• Restarting the service should only happen if it was running prior to the operation.

Local test plan

• npm ci
• npm run lint
• npm test
• npm run build
• npm run docs:check

[Kinin-Code-Offical]

Done via #46
Merge commit: f73b5ee

Verification

• npm ci (PASS)
• npm run lint (PASS)
• npm test (PASS)
• npm run build (PASS)
• npm run docs:check (PASS)