Fix policy form roles; add JSON edit mode

- Replace stale "service" role option with correct set:
  admin, user, guest, viewer, editor, commenter (matches model.go)
- Add Form/JSON tab toggle to policy create form
- JSON tab accepts raw RuleBody JSON with description/priority
- Handler detects rule_json field and parses/validates it
  directly, falling back to field-by-field form mode otherwise

.junie/memory/feedback.md

@@ -0,0 +1,8 @@
+[2026-03-15 19:17] - Updated by Junie
+{
+    "TYPE": "negative",
+    "CATEGORY": "Service reliability",
+    "EXPECTATION": "The Swagger docs endpoint should remain accessible and stable at all times.",
+    "NEW INSTRUCTION": "WHEN swagger/docs endpoint is down or errors THEN Diagnose cause, apply fix, and restore availability immediately"
+}
+

.junie/memory/language.json

@@ -1 +1 @@
-[{"lang":"en","usageCount":3}]
+[{"lang":"en","usageCount":7}]