fix(lib,reconcile,test): address Claude review findings and verify 100% PASS

- lib.sh: distinguish unobservable/headless (rc=2) from unsettled panes in _pane_quiescent; restore 10s quiescence window with early giveup (SKS_EMPTY_GIVEUP)
- reconcile.sh: fix SKILLS_DIR command substitution logic (&& pwd instead of || pwd)
- tests/test_b19_headless_reconcile_fixes.py: implement mutation-proven regression tests for headless prompt bypass, slow-settling panes with persistent counters, and real reconcile.sh SKILLS_DIR evaluation
- deploy/ & IMPROVEMENTS.md: document nats submodule access notes and B-19/B-20 evolution
- Promoted Reviewer Claude's final 100% PASS report (report-119b9f57.md)

.mam.env.example

@@ -116,6 +116,18 @@
 #default: <cwd>/.mam/delegate_job_logs
 # DELEGATE_JOB_LOGS_DIR=/path/to/workspace/.mam/delegate_job_logs
 
+# Max attempts to poll for pane renderer quiescence in send_keys_safe.
+#default: 20
+# SKS_QUIESCENT_TRIES=20
+
+# Interval (seconds) between pane quiescence capture polls.
+#default: 0.5
+# SKS_QUIESCENT_INTERVAL=0.5
+
+# Consecutive empty captures to conclude unobservable/headless mode early.
+#default: 3
+# SKS_EMPTY_GIVEUP=3
+
 # ==============================================================================
 # deploy / distribution source (for forks/mirrors)
 # ==============================================================================