🎯 Watchdog Session-ID Bypass Fix

Toggle CLAUDE_SESSION_ID state to see how the old filter silently bypassed cross-session zombies — and how the new filter catches them.

process.env.CLAUDE_SESSION_ID:

spawn entry:

Filter outcome — OLD vs NEW logic

	OLD filter	NEW filter

The 1-line fix

- if (currentSessionId && spawn.session_id &&
      spawn.session_id !== currentSessionId) continue;
+ if (spawn.session_id &&
      (!currentSessionId || spawn.session_id !== currentSessionId)) continue;

Why this matters

Aspect	Detail
Bug	OLD filter required `currentSessionId` truthy. When hook env lacked `CLAUDE_SESSION_ID`, the entire filter short-circuited to a no-op.
Result	24h cap was the only guard. Overnight gap between sessions (17-18h) fits under 24h. Yesterday's spawn entries fired CRITICAL noise.
Fix	Always drop tagged-as-different-session spawns. Untagged ones still fall through to the 24h cap.
Tests added	+2 cases in `watchdog.test.ts`: (a) unset session_id + cross-session spawn drops, (b) unset session_id + legacy untagged spawn still fires.

Session arc — the bug we papered over and now fixed

PR	What it did	Status
`#1882`	Added 24h zombie cap to silence days-old spawn noise	Right idea, wrong width (24h > 17-18h overnight gap)
`#1952`	Added session-id filter (this PR's bug location)	Right filter, silent bypass when env unset
`#1966`	Rotated subagent-spawns.jsonl at 500KB	Independent — about file size, not staleness
`#1967`	Cross-reference CC 2.1.145 background_tasks[]	Workaround. Hid the user-visible noise but didn't fix the bypass
THIS	Tighten the session-id filter	Actual root-cause fix

Root cause found by ork:debug-investigator agent (~5 min, read-only) after the user asked "lets assess all throughly and properly" and then "use sub agents and skills". The agent ruled out timestamp parse failure, clock skew, and NaN comparison; identified the actual structural issue in 281s.