docs: closed-not-merged PR reconciliation rules (#51)

Documents and enforces rules for closed-not-merged PR reconciliation, direct-master-push prevention, and issue label cleanup.

Rules added:
- Explicit definitions for Merged, Landed, Closed-not-merged, and Reconciled.
- A PR is done only when Gitea reports it merged or reconciliation proves content is present on master.
- Direct push to master is forbidden except as a documented recovery exception.
- PRs closed but not merged trigger the reconciliation process.
- Branch and worktree cleanup is forbidden until merge or reconciliation is confirmed.
- Final reports require PR metadata and Git content verification.

Closes #51.

skills/llm-project-workflow/templates/reconcile-closed-not-merged-pr.md

@@ -0,0 +1,24 @@
+# Reconcile Closed-Not-Merged PR Prompt
+
+You are reconciling PR `<pr-number>` in `<repo-name>` which is closed but `merged=false`.
+
+Rules:
+
+- Do not delete branches or worktrees before reconciliation is complete.
+- Compare the PR's exact content to remote `<default-branch>`.
+- Determine if the content is fully landed, partially landed, or not landed.
+
+Workflow:
+
+1. Verify the PR metadata says `state=closed` and `merged=false`.
+2. Fetch/prune and inspect remote `<default-branch>`.
+3. If fully landed: comment that it landed, remove `status:in-progress`, close issue, and clean up.
+4. If partially landed: reopen issue if needed, create corrective PR for missing pieces, do not clean up.
+5. If not landed: reopen issue/PR, do not clean up.
+
+Final handoff:
+
+- PR metadata (state, merged flag, hash)
+- Git content verification (remote master hash, expected content present or not)
+- reconciliation decision (fully/partially/not landed)
+- issue/label state repaired