[Baseline] Pre-zombie-fix checkpoint

Investigation complete - 5 agents identified root causes:
- periodic_save_check.py: 540 processes/hour (53%)
- Background sync-contexts: 200 processes/hour (20%)
- user-prompt-submit: 180 processes/hour (18%)
- task-complete: 90 processes/hour (9%)
Total: 1,010 zombie processes/hour, 3-7 GB RAM/hour

Phase 1 fixes ready to implement:
1. Reduce periodic save frequency (1min to 5min)
2. Add timeouts to all subprocess calls
3. Remove background sync-contexts spawning
4. Add mutex lock to prevent overlaps

See: FINAL_ZOMBIE_SOLUTION.md for complete analysis

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.claude/.periodic-save-state.json

@@ -1,5 +1,5 @@
 {
-  "active_seconds": 4440,
-  "last_update": "2026-01-17T20:11:36.447287+00:00",
+  "active_seconds": 5760,
+  "last_update": "2026-01-17T20:33:51.483895+00:00",
   "last_save": null
 }