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/resolving-merge-conflicts/SKILL.md

@@ -0,0 +1,14 @@
+---
+name: resolving-merge-conflicts
+description: "Use when you need to resolve an in-progress git merge/rebase conflict."
+---
+
+1. **See the current state** of the merge/rebase. Check git history, and the conflicting files.
+
+2. **Find the primary sources** for each conflict. Understand deeply why each change was made, and what the original intent was. Read the commit messages, check the PRs, check original issues/tickets.
+
+3. **Resolve each hunk.** Preserve both intents where possible. Where incompatible, pick the one matching the merge's stated goal and note the trade-off. Do **not** invent new behaviour. Always resolve; never `--abort`.
+
+4. Discover the project's **automated checks** and run them, typically typecheck, then tests, then format. Fix anything the merge broke.
+
+5. **Finish the merge/rebase.** Stage everything and commit. If rebasing, continue the rebase process until all commits are rebased.

.agents/skills/resolving-merge-conflicts/agents/openai.yaml

@@ -0,0 +1,3 @@
+interface:
+  display_name: "Resolving Merge Conflicts"
+  short_description: "Resolve merge and rebase conflicts"