docs(01-04): add gap-closure plan for device CRUD UI and CSS fixes

Closes 2 gaps from VERIFICATION.md:
- DEV-03: add-device-form + POST/DELETE handlers in app.js
- UI-02: --accent CSS variable rename + panel IDs in index.html

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.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