Fix enrolled host daemon port collisions

[ymichael]

Summary

• allocate and persist a distinct local API port for each enrolled host daemon, and pass it through foreground joins plus generated launchd/systemd services
• validate readiness through /status, requiring the expected hostId, normalized serverUrl, and an active server connection
• turn remaining EADDRINUSE and service startup failures into actionable bb-authored diagnostics
• document the installer override and port-selection behavior

Testing

• sh -n apps/server/src/assets/install-machine.sh
• pnpm exec turbo run typecheck --filter=@bb/host-daemon --filter=bb-app --filter=@bb/server
• pnpm exec turbo run test --filter=@bb/host-daemon --force -- --run src/local-api.test.ts
• pnpm exec turbo run test --filter=bb-app --force -- --run test/index.test.ts
• pnpm exec turbo run test --filter=@bb/server --force -- --run test/app/install-machine-script.test.ts test/app/skeleton.test.ts

Fixes #1121

[SawyerHood]

🚨 SLOP COP 🚨 · review

I am SlopCop. I am reviewing this pull request for security, code quality, performance, architecture, duplication, and end-to-end behavior.

I will post one final review after the parallel checks finish.

[SawyerHood]

🚨 SLOP COP 🚨 · review

ELI5

Each daemon needs a different port.

This change chooses one, but some Linux and multi-install cases can still choose or use the wrong port.

Findings

I found four issues:

1. High: An active Linux service does not restart after its unit changes.
2. Medium: Custom BB_DATA_DIR daemons do not reserve their ports globally.
3. Medium: Concurrent installers can select the same port.
4. Medium: The tests require fixed ports that real enrolled daemons can already use.

I left an inline comment for each issue. I would fix these issues before merge.

Security and performance

I found no new critical security boundary.

The allocation race can still cause EADDRINUSE. A failed connection loop can also take about 105 seconds.

Architecture

The shell script now repeats port validation, allocation, URL normalization, and status parsing.

A typed bb-app allocation command could own this policy. A global registry and lock could make reservations complete and atomic.

The daemon protocol version does not need a change because this pull request does not change the server-daemon wire contract.

Validation

Three GPT-5.6-Sol agents reviewed security, quality, performance, architecture, and end-to-end behavior. A final GPT-5.6-Sol gate confirmed the four findings.

• All affected Turbo type checks passed.
• The host-daemon tests passed.
• The bb-app launcher tests passed.
• The server suite passed 1,344 tests and failed two installer tests.
• One failure confirmed the fixed-port defect.
• The other failure exposed incomplete PATH isolation in the npm fallback fixture.
• The live launcher check accepted the correct enrolled daemon in 21 milliseconds.
• The live launcher check rejected a wrong host identity in 207 milliseconds.
• No browser test applied because this change has no browser route.

I used a comment-only review. I did not approve or request changes through GitHub.