## Why
Locale, timezone, or system clock changes can alter the `ps` start-time text used to identify a running daemon, causing its PID record to be treated as stale.
## What changed
- Record and check native process identities on Linux and macOS, using boot IDs to reject records from previous boots and native process details to detect PID reuse.
- Keep `processStartTime` for older clients and promote verifiable legacy daemon and updater records when the updater starts.
- Retain legacy records and report an error when a live process's start-time text no longer matches. Propagate Windows process-access errors instead of treating inaccessible PIDs as stale.
## Testing
Add regression coverage for locale and timezone changes, altered legacy timestamps, legacy record promotion, PID reuse, previous boots, and macOS process ownership differences. Extend zombie-reaping coverage to native identities and verify that Windows access-denied errors are preserved.
GitOrigin-RevId: b5752497c0e8186bb604fe5dd33f570acc068f20