persistent auth in SQLite, API chat/logs, agent completion via channel

- Auth: move from state.json to SQLite authed_chats table, with memory cache
- Remove Persistent/state.json, all state now in noc.db
- HTTP API: POST /api/chat (end-to-end LLM), GET /api/logs (failed API requests)
- API logging: store raw request/response for 400 errors in api_log table
- Agent completion: spawn_agent sends LifeEvent::AgentDone via channel,
  life loop picks up with full conversation context and responds
- Config structs: derive Clone for HTTP server
- System prompt: instruct LLM not to add timestamps
- Makefile: rsync without --delete to preserve VPS-only tools

Makefile

@@ -34,7 +34,7 @@ deploy: test build
 	scp target/release/noc $(SUITE):~/bin/
 	scp config.suite.yaml $(SUITE):/data/noc/config.yaml
 	scp noc.service.in $(SUITE):/data/noc/
-	scp -r tools/ $(SUITE):/data/noc/tools/
+	rsync -a tools/ $(SUITE):/data/noc/tools/
 	ssh $(SUITE) 'bash -lc "\
 		cd /data/noc \
 		&& sed -e \"s|@REPO@|/data/noc|g\" -e \"s|@PATH@|\$$PATH|g\" noc.service.in > ~/.config/systemd/user/noc.service \