fix: honor slack reply threading

src/slack/monitor.tool-result.test.ts

@@ -283,6 +283,17 @@ describe("monitorSlackProvider tool results", () => {
 
   it("threads replies when incoming message is in a thread", async () => {
     replyMock.mockResolvedValue({ text: "thread reply" });
+    config = {
+      messages: {
+        responsePrefix: "PFX",
+        ackReaction: "👀",
+        ackReactionScope: "group-mentions",
+      },
+      slack: {
+        dm: { enabled: true, policy: "open", allowFrom: ["*"] },
+        replyToMode: "first",
+      },
+    };
 
     const controller = new AbortController();
     const run = monitorSlackProvider({
@@ -315,6 +326,50 @@ describe("monitorSlackProvider tool results", () => {
     expect(sendMock.mock.calls[0][2]).toMatchObject({ threadTs: "456" });
   });
 
+  it("threads top-level replies when replyToMode is all", async () => {
+    replyMock.mockResolvedValue({ text: "thread reply" });
+    config = {
+      messages: {
+        responsePrefix: "PFX",
+        ackReaction: "👀",
+        ackReactionScope: "group-mentions",
+      },
+      slack: {
+        dm: { enabled: true, policy: "open", allowFrom: ["*"] },
+        replyToMode: "all",
+      },
+    };
+
+    const controller = new AbortController();
+    const run = monitorSlackProvider({
+      botToken: "bot-token",
+      appToken: "app-token",
+      abortSignal: controller.signal,
+    });
+
+    await waitForEvent("message");
+    const handler = getSlackHandlers()?.get("message");
+    if (!handler) throw new Error("Slack message handler not registered");
+
+    await handler({
+      event: {
+        type: "message",
+        user: "U1",
+        text: "hello",
+        ts: "123",
+        channel: "C1",
+        channel_type: "im",
+      },
+    });
+
+    await flush();
+    controller.abort();
+    await run;
+
+    expect(sendMock).toHaveBeenCalledTimes(1);
+    expect(sendMock.mock.calls[0][2]).toMatchObject({ threadTs: "123" });
+  });
+
   it("treats parent_user_id as a thread reply even when thread_ts matches ts", async () => {
     replyMock.mockResolvedValue({ text: "thread reply" });
 
@@ -484,6 +539,17 @@ describe("monitorSlackProvider tool results", () => {
 
   it("keeps replies in channel root when message is not threaded", async () => {
     replyMock.mockResolvedValue({ text: "root reply" });
+    config = {
+      messages: {
+        responsePrefix: "PFX",
+        ackReaction: "👀",
+        ackReactionScope: "group-mentions",
+      },
+      slack: {
+        dm: { enabled: true, policy: "open", allowFrom: ["*"] },
+        replyToMode: "first",
+      },
+    };
 
     const controller = new AbortController();
     const run = monitorSlackProvider({
@@ -515,6 +581,50 @@ describe("monitorSlackProvider tool results", () => {
     expect(sendMock.mock.calls[0][2]).toMatchObject({ threadTs: undefined });
   });
 
+  it("forces thread replies when replyToId is set", async () => {
+    replyMock.mockResolvedValue({ text: "forced reply", replyToId: "555" });
+    config = {
+      messages: {
+        responsePrefix: "PFX",
+        ackReaction: "👀",
+        ackReactionScope: "group-mentions",
+      },
+      slack: {
+        dm: { enabled: true, policy: "open", allowFrom: ["*"] },
+        replyToMode: "off",
+      },
+    };
+
+    const controller = new AbortController();
+    const run = monitorSlackProvider({
+      botToken: "bot-token",
+      appToken: "app-token",
+      abortSignal: controller.signal,
+    });
+
+    await waitForEvent("message");
+    const handler = getSlackHandlers()?.get("message");
+    if (!handler) throw new Error("Slack message handler not registered");
+
+    await handler({
+      event: {
+        type: "message",
+        user: "U1",
+        text: "hello",
+        ts: "789",
+        channel: "C1",
+        channel_type: "im",
+      },
+    });
+
+    await flush();
+    controller.abort();
+    await run;
+
+    expect(sendMock).toHaveBeenCalledTimes(1);
+    expect(sendMock.mock.calls[0][2]).toMatchObject({ threadTs: "555" });
+  });
+
   it("reacts to mention-gated room messages when ackReaction is enabled", async () => {
     replyMock.mockResolvedValue(undefined);
     const client = getSlackClient();