feat: show owners a live worker status snapshot

While a worker turn is running, the assistant prompt for the working
proposal's owner includes a compact status card (elapsed time, last
tool activity category with age, per-category counts) built from the
ACP session/update stream the runtime already receives. Other users
still see only the desensitized busy state, and raw update content
never enters the assistant session.

test/fixtures/fake-acp-agent.mjs

@@ -107,6 +107,27 @@ const app = acp.agent({ name: "fake-acp-agent" })
     }
     if (text.startsWith("Execute this confirmed proposal")) {
       const goal = ((text.split("Goal: ")[1] || "").split("\n")[0] || "").trim();
+      if (goal.includes("toolhang")) {
+        await client.notify(acp.methods.client.session.update, {
+          sessionId: params.sessionId,
+          update: { sessionUpdate: "tool_call", toolCallId: "read-1", title: "Read package.json", kind: "read", status: "in_progress" }
+        });
+        await client.notify(acp.methods.client.session.update, {
+          sessionId: params.sessionId,
+          update: { sessionUpdate: "tool_call", toolCallId: "read-2", title: "Read README.md", kind: "read", status: "in_progress" }
+        });
+        await client.notify(acp.methods.client.session.update, {
+          sessionId: params.sessionId,
+          update: { sessionUpdate: "tool_call", toolCallId: "exec-1", title: "bash npm test", kind: "execute", status: "in_progress" }
+        });
+        await new Promise((resolve) => {
+          const done = () => resolve(undefined);
+          pending.set(params.sessionId, done);
+          signal.addEventListener("abort", done, { once: true });
+        });
+        pending.delete(params.sessionId);
+        return { stopReason: "cancelled" };
+      }
       if (goal.includes("hang")) {
         await new Promise((resolve) => {
           const done = () => resolve(undefined);