Auto-review follow-ups for PR #231: feat(server): fall back to FETCHPROXY_WS_PORT for the concentrator port

[github-actions]

Tracking auto-review follow-ups for #231 (verdict: fail).

🔴 Important

• FETCHPROXY_WS_PORT's documented purpose (per-MCP production ports, e.g. for honeybook on a hosted runner) is incompatible with the extension's hardcoded HOST_PORT=37149 in packages/extension-core/src/background/socket.ts:46-47, and contradicts the unmodified sentence directly above the new JSDoc in packages/server/src/ws-server.ts:56-60 stating 'production MCPs all need to share one port for the concentrator to work' — no runtime warning exists when the resolved port diverges from 37149

🟡 Nits

• packages/server/README.md:72's options table wasn't updated to mention the new FETCHPROXY_WS_PORT fallback and still says 'production MCPs all need to share one port,' now out of sync with the top-level README.md

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When addressing the review on #231, resolve each item and add Closes #<this issue> to the PR once everything is genuinely fixed; deferred items stay open here. See the auto-review follow-up convention in CLAUDE.md.