feat: make local proxy ports adaptive instead of preferring 3456

[kaitranntt]

Description

The local OpenAI-compatible proxy currently gravitates toward the shared 3456 default. That port is popular in local development, so users hit avoidable conflicts even when CCS could run on another free local port.

Context

The current proxy flow already persists runtime port state and prints the active port through ccs proxy activate, so the remaining gap is the default selection policy.

Affected Files

• src/proxy/proxy-daemon.ts
• src/proxy/proxy-port-resolver.ts
• src/proxy/proxy-daemon-paths.ts
• tests/integration/proxy/daemon-lifecycle.test.ts
• tests/unit/proxy/proxy-port-resolver.test.ts
• docs/openai-compatible-providers.md

[github-actions]

[bot] Available in 7.73.1-dev.8. Install: ccs update --dev

[kaitranntt]

🎉 This issue has been resolved in version 7.74.0 🎉

The release is available on:

• npm package (@latest)
• GitHub release