fix(agent-pod): stop double-encoding events in agent-run.js

JSON.stringify({id, event: line}) treated the already-JSON `line` as a
plain string, so every event landed in the hub double-encoded (a JSON
string containing escaped JSON, not an object) -- agent-console's
json.Unmarshal into a struct silently failed on every single event.
Now the raw JSON line is spliced directly into the request body.
Also await all in-flight event posts before posting /agent/end, since
those POSTs were fire-and-forget and could reorder past it on the wire.

k8s/apps/agent-pod/agent-run-configmap.yaml

@@ -21,10 +21,17 @@ data:
       await fetch(`${HUB}${path}`, {
         method: "POST",
         headers: { "Content-Type": "application/json" },
-        body: JSON.stringify(body),
+        body,
       }).catch((err) => console.error(`hub post ${path} failed:`, err.message));
     }
 
+    // `rawLine` is already a full JSON object (one per pi --mode json stdout
+    // line) -- embed it as-is rather than JSON.stringify-ing it into a nested
+    // string, or the hub ends up storing an escaped string instead of an event.
+    function postEvent(id, rawLine) {
+      return post("/agent/event", `{"id":${JSON.stringify(id)},"event":${rawLine}}`);
+    }
+
     async function main() {
       const args = process.argv.slice(2);
       const agent = args.shift();
@@ -34,18 +41,22 @@ data:
       }
 
       const id = crypto.randomUUID();
-      await post("/agent/start", { id, agent });
+      await post("/agent/start", JSON.stringify({ id, agent }));
 
       const child = spawn("pi", ["-p", "--mode", "json", ...args], {
         stdio: ["ignore", "pipe", "pipe"],
       });
 
+      // Track in-flight event posts so /agent/end can't race ahead of them --
+      // fetch() isn't awaited per-line (would serialize on network latency), but
+      // 'close' must wait for all of them before reporting done.
+      const pending = [];
       const rl = readline.createInterface({ input: child.stdout });
       rl.on("line", (line) => {
         if (!line.trim()) return;
         try {
           JSON.parse(line); // pi emits one JSON object per line; validate before relay
-          post("/agent/event", { id, event: line });
+          pending.push(postEvent(id, line));
         } catch {
           // non-JSON stdout noise, ignore
         }
@@ -54,7 +65,8 @@ data:
       child.stderr.on("data", (chunk) => process.stderr.write(chunk));
 
       child.on("close", async (code) => {
-        await post("/agent/end", { id, status: code === 0 ? "done" : "error" });
+        await Promise.all(pending);
+        await post("/agent/end", JSON.stringify({ id, status: code === 0 ? "done" : "error" }));
         process.exit(code ?? 1);
       });
     }