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/opencode/internalBridgeTools.test.ts

@@ -15,10 +15,9 @@ describe("OpenCode internal bridge tools", () => {
       hostname: "127.0.0.1",
       port: 0,
       fetch(request) {
-        const url = new URL(request.url);
         receivedToken = request.headers.get("x-agent-internal-token");
-        receivedSessionId = url.searchParams.get("session_id");
-        return Response.json({ task: { task_id: "task-1" } });
+        receivedSessionId = null;
+        return request.json().then((body) => { receivedSessionId = body.session_id; return Response.json({ task: { task_id: "task-1" } }); });
       },
     });
 
@@ -26,8 +25,8 @@ describe("OpenCode internal bridge tools", () => {
       processExecPath(),
       "-e",
       [
-        'import tool from "./.opencode/tools/get_operational_task_context.ts";',
-        'const result = await tool.execute({}, { sessionID: "runtime-session-1" });',
+        'import tool from "./.opencode/tools/memory_manager.ts";',
+        'const result = await tool.execute({ action: "list", scope: "user", reason: "review existing memory" }, { sessionID: "runtime-session-1" });',
         "process.stdout.write(result);",
       ].join("\n"),
     ], {
@@ -58,8 +57,8 @@ describe("OpenCode internal bridge tools", () => {
       processExecPath(),
       "-e",
       [
-        'import tool from "./.opencode/tools/get_operational_task_context.ts";',
-        'await tool.execute({}, { sessionID: "runtime-session-1" });',
+        'import tool from "./.opencode/tools/memory_manager.ts";',
+        'await tool.execute({ action: "list", scope: "user", reason: "review existing memory" }, { sessionID: "runtime-session-1" });',
       ].join("\n"),
     ], {
       cwd: process.cwd(),