Complete activity-core LLM endpoint handoff (LLM-WP-0006)

Switch the custodian triage default from anthropic/claude-sonnet-4 to
google/gemini-2.5-flash, which advertises structured-output support on
OpenRouter. Tighten the OpenRouter adapter to send strict JSON schema
requests and set provider.require_parameters=true so routing only hits
providers that honor the requested response_format.

Update Kubernetes deploy docs and config for the verified coulombcore
handoff: Containerfile build path, image-pull-policy=Never for smoke
pods, credential-routing notes, and live smoke evidence. Mark
LLM-WP-0006 finished with closure notes from 2026-06-18.

llm_connect/_payload.py

@@ -100,7 +100,7 @@ def merge_openai_chat_model_params(payload: dict[str, Any], model_params: dict[s
             "json_schema": {
                 "name": "structured_output",
                 "schema": schema,
-                "strict": False,
+                "strict": True,
             },
         }