fix(slack): thread agent identity through channel reply path (openclaw#27134) thanks @hou-rong

Verified:
- pnpm install --frozen-lockfile
- pnpm build
- pnpm check
- pnpm test:macmini

Co-authored-by: hou-rong <8758438+hou-rong@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

src/slack/monitor/message-handler/dispatch.ts

@@ -9,6 +9,7 @@ import { createReplyPrefixOptions } from "../../../channels/reply-prefix.js";
 import { createTypingCallbacks } from "../../../channels/typing.js";
 import { resolveStorePath, updateLastRoute } from "../../../config/sessions.js";
 import { danger, logVerbose, shouldLogVerbose } from "../../../globals.js";
+import { resolveAgentOutboundIdentity } from "../../../infra/outbound/identity.js";
 import { removeSlackReaction } from "../../actions.js";
 import { createSlackDraftStream } from "../../draft-stream.js";
 import {
@@ -70,6 +71,16 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
   const cfg = ctx.cfg;
   const runtime = ctx.runtime;
 
+  // Resolve agent identity for Slack chat:write.customize overrides.
+  const outboundIdentity = resolveAgentOutboundIdentity(cfg, route.agentId);
+  const slackIdentity = outboundIdentity
+    ? {
+        username: outboundIdentity.name,
+        iconUrl: outboundIdentity.avatarUrl,
+        iconEmoji: outboundIdentity.emoji,
+      }
+    : undefined;
+
   if (prepared.isDirectMessage) {
     const sessionCfg = cfg.session;
     const storePath = resolveStorePath(sessionCfg?.store, {
@@ -190,6 +201,7 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
       textLimit: ctx.textLimit,
       replyThreadTs,
       replyToMode: ctx.replyToMode,
+      ...(slackIdentity ? { identity: slackIdentity } : {}),
     });
     replyPlan.markSent();
   };