fix(agentos-server): fall back to _id lookup in /agents/resolve

Agents registered via the UI or /agents/register have no `agentId` field
set — that field is only stamped by the telemetry projection when the SDK
runs with agent_id=. The resolve endpoint was doing a strict { agentId }
lookup, returning 404 for these agents even though the caller was passing
the valid Mongo _id.

Now falls back to an ObjectId _id lookup when the agentId field miss
occurs, so callers can use the _id returned by /agents/register directly
as their SMOKE_AGENT_ID / agent_id reference without a separate adoption
run.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: abhi-bhat-lyzr

packages/agentos-server/src/routes/agents.ts

@@ -12,6 +12,7 @@
 //   chattable / scheduleable. Secrets stay in process.env.
 
 import { Router, type Router as IRouter } from "express";
+import { ObjectId } from "mongodb";
 import { chatPinsColl, chatSessionsColl, messagesColl, registryColl, sessionsColl, type RegistryDoc } from "../mongo.js";
 import { listLiveSandboxes } from "../upstream.js";
 import { agentLogStore } from "../stores/agent-log-store.js";
@@ -120,7 +121,13 @@ agentsRouter.post("/agents/resolve", authorize("agents:read"), async (req, res,
     if (!agentId) {
       return res.status(400).json({ error: { code: "BAD_REQUEST", message: "`agentId` required" } });
     }
-    const doc = await (await registryColl()).findOne({ agentId });
+    const coll = await registryColl();
+    let doc = await coll.findOne({ agentId });
+    // Fall back to ObjectId (_id) lookup — lets callers use the Mongo _id
+    // returned by /agents/register as the agent_id reference.
+    if (!doc && ObjectId.isValid(agentId)) {
+      doc = await coll.findOne({ _id: new ObjectId(agentId) });
+    }
     if (!doc || !canRead(res.locals.principal, doc)) {
       return res.status(404).json({ error: { code: "NOT_FOUND", message: `no agent with agentId=${agentId}` } });
     }