feat(slack): add configurable loading messages and typing status

Add support for customizing the Slack thread status messages shown while
processing requests:

- loadingMessages: string[] - Array of messages that rotate randomly
  during processing (passed to Slack's assistant.threads.setStatus API)
- typingStatus: string - Custom typing indicator text (default: 'is typing...')

These can be configured per Slack account in channels.slack config:

```yaml
channels:
  slack:
    typingStatus: 'is thinking...'
    loadingMessages:
      - 'Pondering...'
      - 'Processing...'
      - 'Almost there...'
```

src/config/types.slack.ts

@@ -77,6 +77,10 @@ export type SlackThreadConfig = {
 export type SlackAccountConfig = {
   /** Optional display name for this account (used in CLI/UI lists). */
   name?: string;
+  /** Custom loading messages shown while processing (rotates randomly). */
+  loadingMessages?: string[];
+  /** Status text shown while typing (default: "is typing..."). */
+  typingStatus?: string;
   /** Slack connection mode (socket|http). Default: socket. */
   mode?: "socket" | "http";
   /** Slack signing secret (required for HTTP mode). */

src/slack/monitor/context.ts

@@ -111,7 +111,10 @@ export type SlackMonitorContext = {
     channelId: string;
     threadTs?: string;
     status: string;
+    loadingMessages?: string[];
   }) => Promise<void>;
+  loadingMessages?: string[];
+  typingStatus: string;
 };
 
 export function createSlackMonitorContext(params: {
@@ -148,6 +151,8 @@ export function createSlackMonitorContext(params: {
   ackReactionScope: string;
   mediaMaxBytes: number;
   removeAckAfterReply: boolean;
+  loadingMessages?: string[];
+  typingStatus?: string;
 }): SlackMonitorContext {
   const channelHistories = new Map<string, HistoryEntry[]>();
   const logger = getChildLogger({ module: "slack-auto-reply" });
@@ -247,14 +252,18 @@ export function createSlackMonitorContext(params: {
     channelId: string;
     threadTs?: string;
     status: string;
+    loadingMessages?: string[];
   }) => {
     if (!p.threadTs) return;
-    const payload = {
+    const payload: Record<string, unknown> = {
       token: params.botToken,
       channel_id: p.channelId,
       thread_ts: p.threadTs,
       status: p.status,
     };
+    if (p.loadingMessages && p.loadingMessages.length > 0) {
+      payload.loading_messages = p.loadingMessages;
+    }
     const client = params.app.client as unknown as {
       assistant?: {
         threads?: {
@@ -400,5 +409,7 @@ export function createSlackMonitorContext(params: {
     resolveChannelName,
     resolveUserName,
     setSlackThreadStatus,
+    loadingMessages: params.loadingMessages,
+    typingStatus: params.typingStatus ?? "is typing...",
   };
 }

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

@@ -63,7 +63,8 @@ export async function dispatchPreparedSlackMessage(prepared: PreparedSlackMessag
       await ctx.setSlackThreadStatus({
         channelId: message.channel,
         threadTs: statusThreadTs,
-        status: "is typing...",
+        status: ctx.typingStatus,
+        loadingMessages: ctx.loadingMessages,
       });
     },
     stop: async () => {

src/slack/monitor/provider.ts

@@ -123,6 +123,8 @@ export async function monitorSlackProvider(opts: MonitorSlackOpts = {}) {
   const ackReactionScope = cfg.messages?.ackReactionScope ?? "group-mentions";
   const mediaMaxBytes = (opts.mediaMaxMb ?? slackCfg.mediaMaxMb ?? 20) * 1024 * 1024;
   const removeAckAfterReply = cfg.messages?.removeAckAfterReply ?? false;
+  const loadingMessages = slackCfg.loadingMessages;
+  const typingStatus = slackCfg.typingStatus;
 
   const receiver =
     slackMode === "http"
@@ -204,6 +206,8 @@ export async function monitorSlackProvider(opts: MonitorSlackOpts = {}) {
     ackReactionScope,
     mediaMaxBytes,
     removeAckAfterReply,
+    loadingMessages,
+    typingStatus,
   });
 
   const handleSlackMessage = createSlackMessageHandler({ ctx, account });