chore(agents): install mattpocock skills + per-repo agent config

- 38 skills from mattpocock/skills into .agents/skills/ (symlinked into
  .claude/skills/ for Claude Code)
- skills-lock.json for reproducible installs
- docs/agents/: issue-tracker (Gitea via tea CLI), triage-labels
  (default five-role vocabulary), domain docs (single-context)
- CLAUDE.md: add '## Agent skills' section pointing at docs/agents/
- .gitignore: un-ignore docs/agents/ under the local /docs/* rule

.agents/skills/loop-me/agents/openai.yaml

@@ -0,0 +1,5 @@
+interface:
+  display_name: "Loop Me"
+  short_description: "Spec the workflows you want to build"
+policy:
+  allow_implicit_invocation: false