fix(code): tighten guided-manual-qa service readiness

[shafty023]

Summary

Tightens the environment readiness rules in the guided-manual-qa skill so a QA session doesn't start against a service that isn't actually up, or against ports shared with another worker.

• Before picking a control launcher that binds fixed ports, check whether it supports isolated ports, sessions, or project names for concurrent workers. If it doesn't, use a documented manual isolated stack and record exact process ownership proof.
• A parent supervisor, launchd wrapper, or control command that reports started no longer counts as ready. The actual listener and the route-owned ready selector must be proven before a checkpoint is presented.
• If a wrapper hangs before it spawns the child or listener, run one bounded foreground diagnostic of the same documented command. This tells a wrapper failure apart from an app or runtime failure. Stop the diagnostic before trying a fallback.

Bumps code to v1.16.2 and adds the CHANGELOG entry.

Testing

• npm test in tools/guided-manual-qa: 46 tests pass, including the skill contract tests that pin SKILL.md text.

[mikeangstadt]

Good tightening. The "started means started" distinction is the one that actually bites in practice. Version bump and CHANGELOG line up, 46 tests still green. One note on test pinning below, not blocking.