feat: add prgs-reconciler profile model and role detection (Closes #304)

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

docs/gitea-execution-profiles.md

@@ -226,6 +226,27 @@ explicit operator-directed closure of a contaminated PR). If `close_pr` ever
 resolves as unknown, agents must fail closed rather than fall back to the
 edit path.
 
+## Reconciler profile for already-landed open PRs (#304)
+
+Normal author and reviewer profiles must not gain broad `gitea.pr.close`
+authority. Already-landed open PRs need a dedicated reconciler profile such
+as `prgs-reconciler` with a narrow operation set:
+
+- `gitea.read`
+- `gitea.pr.comment`
+- `gitea.issue.comment`
+- `gitea.issue.close`
+- `gitea.pr.close`
+
+Forbidden on reconciler profiles: `gitea.pr.approve`, `gitea.pr.merge`,
+`gitea.pr.review`, `gitea.pr.create`, `gitea.branch.push`, and
+`gitea.repo.commit`.
+
+Launch a static `gitea-reconciler` MCP namespace with
+`GITEA_MCP_PROFILE=prgs-reconciler`. Profile shape is validated by
+`reconciler_profile.assess_reconciler_profile`; the gated close MCP tool and
+ancestor proofs ship with the #310 reconciler close stack.
+
 ## Identity and fail-closed rules
 
 Before **any** mutating action, a workflow must know both: