feat(semantic): curator-driven protocol hardening — decision memory + relation repair

- Add @RATIONALE/@REJECTED to 103+ C4/C5 contracts across backend core, services, API routes, and frontend models
- Fix 109 unresolved @RELATION edges (Auth.*, SupersetClient.*, AgentChat.*, ADR cross-refs)
- Add 13 @ingroup tags for DSA/HCA attention grouping
- Repair 29 stale graph edges via index rebuild
- Update .kilo agent prompts and skills for GRACE-Poly v2.6 compliance
- Git integration: merge routes, branch lifecycle, remote providers, UX components
- 0 broken anchor pairs, index rebuilt with 0 parse warnings

backend/src/agent/_persistence.py

@@ -340,7 +340,7 @@ async def prefetch_dashboards(env_id: str) -> str:
 # @POST Conversation + messages saved via POST /api/agent/conversations/save.
 # @SIDE_EFFECT HTTP POST to FastAPI; writes to AgentConversation and AgentMessage tables.
 # @DATA_CONTRACT Input: (conv_id, user_text, user_id, assistant_text) -> Output: None (side-effect only)
-# @RELATION DISPATCHES -> [Api.Agent.Conversations]
+# @RELATION DISPATCHES -> [AgentChat.Api.Conversations]
 # @RATIONALE Anonymous Gradio sessions (anon_ prefix) default to "admin" because the agent runs in an internal network behind an auth proxy — all users within the network are trusted.
 # @REJECTED Requiring explicit authentication for Gradio was rejected — the agent is designed for internal-network use where the auth proxy handles auth; adding a separate auth layer would create unnecessary friction and duplicate the proxy's responsibility.
 async def save_conversation(conv_id: str, user_text: str, user_id: str = "admin", assistant_text: str = "") -> None: