feat(slack): add dm-specific replyToMode configuration (#1442)

Adds support for separate replyToMode settings for DMs vs channels:

- Add channels.slack.dm.replyToMode for DM-specific threading
- Keep channels.slack.replyToMode as default for channels
- Add resolveSlackReplyToMode helper to centralize logic
- Pass chatType through threading resolution chain

Usage:
```json5
{
  channels: {
    slack: {
      replyToMode: "off",     // channels
      dm: {
        replyToMode: "all"    // DMs always thread
      }
    }
  }
}
```

When dm.replyToMode is set, DMs use that mode; channels use the
top-level replyToMode. Backward compatible when not configured.

src/auto-reply/reply/agent-runner.ts

@@ -136,6 +136,7 @@ export async function runReplyAgent(params: {
     followupRun.run.config,
     replyToChannel,
     sessionCtx.AccountId,
+    sessionCtx.ChatType,
   );
   const applyReplyToMode = createReplyToModeFilterForChannel(replyToMode, replyToChannel);
   const cfg = followupRun.run.config;

src/auto-reply/reply/followup-runner.ts

@@ -204,6 +204,7 @@ export function createFollowupRunner(params: {
         queued.run.config,
         replyToChannel,
         queued.originatingAccountId,
+        queued.originatingChatType,
       );
 
       const replyTaggedPayloads: ReplyPayload[] = applyReplyThreading({

src/auto-reply/reply/get-reply-run.ts

@@ -358,6 +358,7 @@ export async function runPreparedReply(
     originatingTo: ctx.OriginatingTo,
     originatingAccountId: ctx.AccountId,
     originatingThreadId: ctx.MessageThreadId,
+    originatingChatType: ctx.ChatType,
     run: {
       agentId,
       agentDir,

src/auto-reply/reply/queue/types.ts

@@ -39,6 +39,8 @@ export type FollowupRun = {
   originatingAccountId?: string;
   /** Thread id for reply routing (Telegram topic id or Matrix thread event id). */
   originatingThreadId?: string | number;
+  /** Chat type for context-aware threading (e.g., DM vs channel). */
+  originatingChatType?: string;
   run: {
     agentId: string;
     agentDir: string;

src/auto-reply/reply/reply-threading.test.ts

@@ -31,6 +31,33 @@ describe("resolveReplyToMode", () => {
     expect(resolveReplyToMode(cfg, "discord")).toBe("first");
     expect(resolveReplyToMode(cfg, "slack")).toBe("all");
   });
+
+  it("uses dm-specific replyToMode for Slack DMs when configured", () => {
+    const cfg = {
+      channels: {
+        slack: {
+          replyToMode: "off",
+          dm: { replyToMode: "all" },
+        },
+      },
+    } as ClawdbotConfig;
+    expect(resolveReplyToMode(cfg, "slack", null, "direct")).toBe("all");
+    expect(resolveReplyToMode(cfg, "slack", null, "channel")).toBe("off");
+    expect(resolveReplyToMode(cfg, "slack", null, undefined)).toBe("off");
+  });
+
+  it("falls back to top-level replyToMode when dm.replyToMode is not configured", () => {
+    const cfg = {
+      channels: {
+        slack: {
+          replyToMode: "first",
+          dm: { enabled: true },
+        },
+      },
+    } as ClawdbotConfig;
+    expect(resolveReplyToMode(cfg, "slack", null, "direct")).toBe("first");
+    expect(resolveReplyToMode(cfg, "slack", null, "channel")).toBe("first");
+  });
 });
 
 describe("createReplyToModeFilter", () => {

src/auto-reply/reply/reply-threading.ts

@@ -9,12 +9,14 @@ export function resolveReplyToMode(
   cfg: ClawdbotConfig,
   channel?: OriginatingChannelType,
   accountId?: string | null,
+  chatType?: string | null,
 ): ReplyToMode {
   const provider = normalizeChannelId(channel);
   if (!provider) return "all";
   const resolved = getChannelDock(provider)?.threading?.resolveReplyToMode?.({
     cfg,
     accountId,
+    chatType,
   });
   return resolved ?? "all";
 }