fix(regression): hydrate run-scoped tool event metadata

src/gateway/server-chat.agent-events.test.ts

@@ -716,6 +716,71 @@ describe("agent event handler", () => {
     resetAgentRunContextForTest();
   });
 
+  it("hydrates run-scoped tool events with session ownership metadata", () => {
+    const { broadcastToConnIds, toolEventRecipients, handler } = createHarness({
+      resolveSessionKeyForRun: () => "session-1",
+    });
+
+    vi.mocked(loadGatewaySessionRow).mockReturnValue({
+      key: "session-1",
+      kind: "direct",
+      spawnedBy: "agent:main:main",
+      spawnedWorkspaceDir: "/tmp/subagent",
+      forkedFromParent: true,
+      spawnDepth: 2,
+      subagentRole: "orchestrator",
+      subagentControlScope: "children",
+      lastThreadId: 42,
+      fastMode: true,
+      verboseLevel: "on",
+      updatedAt: 1_200,
+    });
+
+    registerAgentRunContext("run-tool-owner", { sessionKey: "session-1", verboseLevel: "off" });
+    toolEventRecipients.add("run-tool-owner", "conn-run");
+
+    handler({
+      runId: "run-tool-owner",
+      seq: 1,
+      stream: "tool",
+      ts: 1_234,
+      data: {
+        phase: "start",
+        name: "exec",
+        toolCallId: "tool-run-1",
+        args: { command: "echo hi" },
+      },
+    });
+
+    expect(broadcastToConnIds).toHaveBeenCalledTimes(1);
+    expect(broadcastToConnIds).toHaveBeenCalledWith(
+      "agent",
+      expect.objectContaining({
+        runId: "run-tool-owner",
+        sessionKey: "session-1",
+        spawnedBy: "agent:main:main",
+        spawnedWorkspaceDir: "/tmp/subagent",
+        forkedFromParent: true,
+        spawnDepth: 2,
+        subagentRole: "orchestrator",
+        subagentControlScope: "children",
+        lastThreadId: 42,
+        fastMode: true,
+        verboseLevel: "on",
+        stream: "tool",
+        ts: 1_234,
+        data: expect.objectContaining({
+          phase: "start",
+          name: "exec",
+          toolCallId: "tool-run-1",
+          args: { command: "echo hi" },
+        }),
+      }),
+      new Set(["conn-run"]),
+    );
+    resetAgentRunContextForTest();
+  });
+
   it("broadcasts terminal session status to session subscribers on lifecycle end", () => {
     const { broadcastToConnIds, sessionEventSubscribers, handler } = createHarness({
       resolveSessionKeyForRun: () => "session-finished",

src/gateway/server-chat.ts

@@ -770,7 +770,11 @@ export function createAgentEventHandler({
       // messages to messaging surfaces (Telegram, Discord, etc.).
       const recipients = toolEventRecipients.get(evt.runId);
       if (recipients && recipients.size > 0) {
-        broadcastToConnIds("agent", toolPayload, recipients);
+        broadcastToConnIds(
+          "agent",
+          sessionKey ? { ...toolPayload, ...buildSessionEventSnapshot(sessionKey) } : toolPayload,
+          recipients,
+        );
       }
       // Session subscribers power operator UIs that attach to an existing
       // in-flight session after the run has already started. Those clients do