[jlongster]

Ported from anomalyco/opencode-pty#30. Part of the stack for anomalyco/opencode-pty#25. Builds directly on dev; no prerequisite.

Issue for this PR

Related to anomalyco/opencode-pty#25

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

• Behaviour-preserving refactor: the 10 ms accept loop is unchanged. This PR prepares the loop to become readiness-driven in the next PR.
• New daemon::Control (packages/process-daemon/src/daemon/control.rs) holds a private stop flag and the ownership mutex, and is now the only way to stop the daemon or mutate ownership.
  • request_stop takes the ownership lock, so the next PR can wake the accept loop under that same lock.
• run is split into bind → Control → serve. Ownership is still created after bind, as before.
• Handler completion is tracked with a done flag set by a drop guard in the handler thread (the reap check still also accepts is_finished()). The next PR adds a wake there.
• Ownership::with_timeouts lets tests use short starting/handoff deadlines.
• New in-process unix tests in packages/process-daemon/src/daemon/server.rs, using a TestDaemon fixture that runs serve on a temp socket:
  • shutdown_request_stops_immediately
  • owner_shutdown_stops_immediately
  • owner_disconnect_without_handoff_stops_immediately
  • starting_deadline_fires_on_time
  • waiting_deadline_fires_on_time
  • handoff_claim_transfers_without_spurious_stop

Ported from the opencode-pty commit; the only difference is that connection handlers are spawned with plain thread::spawn, as on dev.

How did you verify your code works?

• Port validation (macOS arm64, Rust 1.90.0, in packages/process-daemon): cargo fmt --check, cargo clippy --locked --all-targets --all-features -- -D warnings, and cargo test --locked --lib (53 passed) pass.
• On the stack tip (daemon-windows-poll) the full macOS CI test selection and Windows/Linux cross clippy also pass.
• Original PR: the macOS CI test selection passed: cargo test --locked --lib --test service --test runtime --test ownership --test rows --test ghostty-effects (lib 47, ghostty-effects 5, ownership 8, rows 1, runtime 8 + 1 ignored, service 9), and cross clippy with -D warnings passed for x86_64-pc-windows-msvc and x86_64-unknown-linux-gnu (--all-targets --all-features, ghostty-vt link libs stubbed). Windows and Linux tests rely on CI.

Screenshots / recordings

N/A, internal daemon change.

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR