feat: add merged PR cleanup reconciliation report (#269)

Implement gitea_reconcile_merged_cleanups with dry-run reporting for merged
PR remote branches and local branches/ worktrees, plus confirmation-gated
execute mode. Safety gates cover protected branches, open PR references,
active issue locks, dirty worktrees, and delete_branch capability.

Closes #269

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

tests/test_mcp_server.py

@@ -24,6 +24,7 @@ from mcp_server import (  # noqa: E402
     gitea_merge_pr,
     gitea_review_pr,
     gitea_delete_branch,
+    gitea_reconcile_merged_cleanups,
     gitea_edit_pr,
     gitea_get_file,
     gitea_commit_files,
@@ -990,6 +991,60 @@ class TestDeleteBranch(unittest.TestCase):
         self.assertIn("feat%2Fbranch", url)
 
 
+# ---------------------------------------------------------------------------
+# Reconcile merged cleanups (#269)
+# ---------------------------------------------------------------------------
+READ_ENV = {
+    "GITEA_ALLOWED_OPERATIONS": "gitea.read",
+}
+
+
+class TestReconcileMergedCleanups(unittest.TestCase):
+
+    @patch("mcp_server.api_get_all")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_dry_run_builds_report_without_mutations(self, _auth, mock_api_get_all):
+        mock_api_get_all.side_effect = [
+            [
+                {
+                    "number": 50,
+                    "title": "merged feature",
+                    "body": "Closes #50",
+                    "merged": True,
+                    "merged_at": "2026-07-06T12:00:00Z",
+                    "merge_commit_sha": "deadbeef",
+                    "head": {"ref": "feat/issue-50-example", "sha": "cafebabe"},
+                }
+            ],
+            [],
+        ]
+        with patch.dict(os.environ, READ_ENV, clear=True):
+            with patch(
+                "mcp_server._remote_branch_exists",
+                return_value=True,
+            ):
+                with patch(
+                    "mcp_server.merged_cleanup_reconcile.is_head_ancestor_of_ref",
+                    return_value=True,
+                ):
+                    result = gitea_reconcile_merged_cleanups(
+                        dry_run=True,
+                        remote="prgs",
+                        limit=10,
+                    )
+        self.assertTrue(result["success"])
+        self.assertTrue(result["dry_run"])
+        self.assertFalse(result["executed"])
+        self.assertEqual(result["merged_pr_count"], 1)
+        self.assertEqual(result["entries"][0]["issue_number"], 50)
+
+    def test_execute_requires_confirmation(self):
+        with patch.dict(os.environ, READ_ENV, clear=True):
+            with self.assertRaises(ValueError) as ctx:
+                gitea_reconcile_merged_cleanups(dry_run=False, execute_confirmed=False)
+        self.assertIn("execute_confirmed", str(ctx.exception))
+
+
 # ---------------------------------------------------------------------------
 # Edit PR
 # ---------------------------------------------------------------------------