integ: merge ORCH-068 reconciler livelock fix

# Conflicts:
#	docs/architecture/README.md
#	src/reconciler.py

.env.example

@@ -117,6 +117,15 @@ ORCH_RECONCILE_GRACE_OVERRIDES_JSON=
 ORCH_RECONCILE_NOTIFY_UNBLOCK=true
 ORCH_RECONCILE_SKIP_BLOCKED_ENABLED=true
 
+# ORCH-068: TTL (seconds) for the per-project Plane states cache (plane_sync
+# _STATES_CACHE). Historically the cache lived for the whole process lifetime,
+# so a status added to Plane after start was invisible until a restart
+# ("stale set -> no pipeline action"). With a TTL the entry self-heals by
+# re-fetching /states/ once it expires (reuses reload_project_states()).
+#   >0  -> re-fetch after this many seconds (default 300 = 5 min);
+#   0   -> disable TTL -> strictly the previous lifetime cache (back-compat).
+ORCH_PLANE_STATES_TTL_S=300
+
 # ORCH-065: job-reaper + proactive merge-lease reclaim. A background daemon thread
 # (src/job_reaper.py, started LAST in main.lifespan after requeue_running_jobs) reaps
 # zombie 'running' jobs whose monitor/process died before writing the terminal status