feat(matrix): land QA follow-ups and refresh docs

- harden Matrix onboarding/chat lifecycle after manual QA
- refresh README and Matrix docs to match current behavior
- add local ignores for runtime artifacts and include current planning/report docs

Closes #7
Closes #9
Closes #14

.planning/config.json

@@ -25,7 +25,8 @@
     "text_mode": false,
     "research_before_questions": false,
     "discuss_mode": "discuss",
-    "skip_discuss": false
+    "skip_discuss": false,
+    "_auto_chain_active": false
   },
   "hooks": {
     "context_warnings": true