[firstmate#285] fix(watcher): make PID identity locale-invariant

[github-actions]

Decision needed - firstmate#285

PR review by pchuri · merge-ready

fix(watcher): make PID identity locale-invariant

Situation

• Compliance: pass
• Tests: green
• Notes: compliance=pass tests=green

Triage

• Summary: Pins LC_ALL=C on the ps call inside firstmate's fm_pid_identity() so the watcher's PID-identity string (used for lock/liveness matching) no longer varies with the caller's locale, and adds a colocated regression test proving byte-identical output under LC_ALL/LC_TIME set to ko_KR.UTF-8.
• Product implications: Routine internal reliability fix, not something needing owner discussion: it's a narrow, well-isolated one-line locale bug fix with a direct regression test, a doc-comment update, and no behavioral change for the existing C-locale case; verified that all fm_pid_identity call sites (fm-watch.sh, fm-wake-lib.sh, fm-turnend-guard.test.sh) funnel through the single patched function.
• Recommended next step: merge - small, correctly scoped locale bug fix with adequate test coverage and no unrelated changes

Recommended action

Merge - compliance and tests are green.

Your decision

Tick one box for a quick call, or reply with a slash-command (/merge, /close, /decline <reason>, /hold, /comment <text>, /request-changes <text>):

• Merge it
• Close / decline
• Investigate - deep code-grounded review (leaves this card open)
• Hold - I'll handle this manually

_{Only the repository owner can drive this decision - everyone else's edits and comments are ignored.}

[github-actions]

Merged firstmate#285 (squash).