chore: update mention gating docs and tests

src/imessage/monitor.test.ts

@@ -139,6 +139,36 @@ describe("monitorIMessageProvider", () => {
     expect(replyMock).toHaveBeenCalled();
   });
 
+  it("allows group messages when requireMention is true but no mentionPatterns exist", async () => {
+    config = {
+      ...config,
+      routing: { groupChat: { mentionPatterns: [] }, allowFrom: [] },
+      imessage: { groups: { "*": { requireMention: true } } },
+    };
+    const run = monitorIMessageProvider();
+    await waitForSubscribe();
+
+    notificationHandler?.({
+      method: "message",
+      params: {
+        message: {
+          id: 12,
+          chat_id: 777,
+          sender: "+15550001111",
+          is_from_me: false,
+          text: "hello group",
+          is_group: true,
+        },
+      },
+    });
+
+    await flush();
+    closeResolve?.();
+    await run;
+
+    expect(replyMock).toHaveBeenCalled();
+  });
+
   it("prefixes tool and final replies with responsePrefix", async () => {
     config = {
       ...config,