fix(daemon): stop the lifetime-lock probe from dropping a held lock

[AmirF194]

While chasing #2162 I found a real, separate bug in posix_lifetime_lock_probe (src/daemon/ipc.c): when the in-process registry says this process already holds the lifetime lock, it still opens a throwaway fd on the lock file just to close it again and return 1. fcntl(2) record locks are scoped to (process, inode), not (fd, inode), so that close silently drops the real lock too, even though the reservation's own fd stays open.

Two probes back to back are enough to lose it. I wrote a test that acquires the reservation, probes it twice, then forks a genuinely separate process that tries to take the same lock directly. On main it succeeds, the lock is gone. With the fix it fails as expected.

Fix: check the in-process claim before opening anything and return early. That branch only ever needed to trust the registry, not touch the file.

scripts/test.sh --suites daemon_ipc: the new test fails on main (child_result == 1), 50 passed / 1 skipped with the fix.

Not a fix for #2162 itself, I ran into this while reading that code, it's a separate bug.

[github-actions]

Thanks for opening this — it has been seen, and it is queued.

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Current review status: working through a backlog. 0.9.1-rc.1 is out, so the release freeze that held reviews is over — but it left a large queue of open pull requests behind it, and we are reading through them oldest-first. The background is in discussion #1144.

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If this fixes a bug, a reproduction we can run is worth more than a description of the symptom.

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