feat(agent): support Responses steering and project-aware tools

Use the dedicated TJWATER_AGENT_URL and Responses stream protocol. Keep running
turns active while users steer or queue follow-ups and edit pending delivery.
Refresh the model catalog before generation and preserve approval mode selection.

Integrate scoped investigation messaging/presentation, geographic place selection,
current Agent composer styles and supporting workbench contracts.

Validation: 77 focused Vitest checks, 21 browser cases, lint, typecheck and
production build. Preserve direct Server/Agent routing and project authentication.

public/runtime-config.js

@@ -4,6 +4,7 @@ globalThis.__TJWATER_CONFIG__ = {
   TJWATER_KEYCLOAK_CLIENT_ID: "next-tjwater",
   TJWATER_MAPBOX_ACCESS_TOKEN: "",
   TJWATER_TIANDITU_TOKEN: "",
+  TJWATER_AGENT_URL: "http://127.0.0.1:8787",
   TJWATER_SERVER_API_BASE_URL: "http://127.0.0.1:8000",
   TJWATER_WORKBENCH_RUNTIME_MODE: "auto"
 };