feat(agent): unify MCP tools and adopt Responses delivery

Move project and host queries into native MCP with host-owned OAuth/context,
while retaining memory, skills, actions and publication plugins. Add nearby-model
queries and explicit chat/task/learning model defaults.

Adopt Responses HTTP/SSE and native steer/queue inbox delivery, preserving scoped
session ownership, pending input edits and investigation communication.

Disable local-provider discovery: Server /health allowed native vLLM to probe
/v1/models on port 8000. A native before/after regression prevents recurrence.

Validation: 170 focused Bun tests; service/plugin typechecks; native discovery,
provider-discovery and input-inbox smoke checks; no paid model inference.

tests/routes/agentTrigger.test.ts

@@ -40,7 +40,7 @@ describe("agent event trigger", () => {
 
   it("keeps event entry and action-tool instructions consistent with report-driven completion", () => {
     const prompt = buildAgentTriggerPrompt(agentTriggerContextSchema.parse(trigger));
-    expect(prompt).toContain("get_operational_task_context");
+    expect(prompt).toContain("mcp_tjwater_get_task_context");
     expect(prompt).toContain("final/insufficient_data");
     expect(prompt).toContain("正常结束本轮");
     expect(prompt).toContain("权限拒绝和接口错误不能证明数据缺失");