chore: dev loop prompt rewrite + branch safety + tox conventions

- timmy-loop-prompt.md: full rewrite (76→209 lines) with PR-only workflow,
  tox environments, git hooks, Kimi dispatch safety block, conventional commits
- kimi-code skill: added Branch & Convention Safety section
- memories/MEMORY.md: updated with branch protection notes
- config.yaml: removed dead kimi API key
- cron/jobs.json: updated scheduled jobs
- channel_directory.json: minor update
- .gitignore: exclude queue/ and *.db

channel_directory.json

@@ -1,5 +1,5 @@
 {
-  "updated_at": "2026-03-14T17:59:29.552651",
+  "updated_at": "2026-03-14T21:24:54.914098",
   "platforms": {
     "discord": [
       {