fix(profiles): canonical reconciler ops and guard raw branch delete (#687)

Address REQUEST_CHANGES on PR #688:

- migrate_profiles: emit fully canonical reconciler/author/reviewer defaults;
  canonicalize explicit ops; fail if reconciler loses required pr.close/read
- gitea_delete_branch: deny reconciler (and non-author roles); refuse
  preservation/protected branches before any API call
- gitea_cleanup_merged_pr_branch: require reconciler role only; block
  preservation/evidence branches via branch_cleanup_guard
- docs: end-to-end operator runbook for profile migrate/apply/reconnect/cleanup
- tests: migration canonicalization, idempotency, raw-delete denial, guarded
  cleanup success and unmerged/preserve rejections

Closes #687.

tests/test_audit_reconciliation_mode.py

@@ -27,7 +27,13 @@ from task_capability_map import required_permission, required_role
 
 DELETE_PROFILE = {
     "profile_name": "prgs-author-delete",
-    "allowed_operations": ["gitea.read", "gitea.branch.delete"],
+    "role": "author",
+    "allowed_operations": [
+        "gitea.read",
+        "gitea.pr.create",
+        "gitea.branch.push",
+        "gitea.branch.delete",
+    ],
     "forbidden_operations": [],
     "audit_label": "prgs-author-delete",
 }