feat: moderator bot for turn handoff messages

Add a dedicated moderator Discord bot that sends handoff messages when
the current speaker says NO_REPLY. This solves the wakeup problem.

Flow:
1. Agent A is current speaker, receives message
2. Agent A responds with NO_REPLY
3. Plugin detects NO_REPLY in message_sent hook, advances turn to Agent B
4. Plugin sends via moderator bot: '轮到（@AgentB）了，如果没有想说的请直接回复NO_REPLY'
5. This real Discord message triggers Agent B's session
6. Turn manager allows Agent B to respond

Implementation:
- moderatorBotToken config field for the moderator bot's Discord token
- userIdFromToken() extracts Discord user ID from bot token (base64)
- resolveDiscordUserId() maps accountId → Discord user ID via account tokens
- sendModeratorMessage() calls Discord REST API directly
- message_received ignores moderator bot messages (transparent to turn state)
- Moderator bot is NOT in the turn order

plugin/index.ts

@@ -239,6 +239,61 @@ function buildAgentIdentity(api: OpenClawPluginApi, agentId: string): string | u
   return `你是 ${name}（Discord 账号: ${accountId}）。`;
 }
 
+// --- Moderator bot helpers ---
+
+/** Extract Discord user ID from a bot token (base64-encoded in first segment) */
+function userIdFromToken(token: string): string | undefined {
+  try {
+    const segment = token.split(".")[0];
+    // Add padding
+    const padded = segment + "=".repeat((4 - (segment.length % 4)) % 4);
+    return Buffer.from(padded, "base64").toString("utf8");
+  } catch {
+    return undefined;
+  }
+}
+
+/** Resolve accountId → Discord user ID by reading the account's bot token from config */
+function resolveDiscordUserId(api: OpenClawPluginApi, accountId: string): string | undefined {
+  const root = (api.config as Record<string, unknown>) || {};
+  const channels = (root.channels as Record<string, unknown>) || {};
+  const discord = (channels.discord as Record<string, unknown>) || {};
+  const accounts = (discord.accounts as Record<string, Record<string, unknown>>) || {};
+  const acct = accounts[accountId];
+  if (!acct?.token || typeof acct.token !== "string") return undefined;
+  return userIdFromToken(acct.token);
+}
+
+/** Get the moderator bot's Discord user ID from its token */
+function getModeratorUserId(config: WhisperGateConfig): string | undefined {
+  if (!config.moderatorBotToken) return undefined;
+  return userIdFromToken(config.moderatorBotToken);
+}
+
+/** Send a message as the moderator bot via Discord REST API */
+async function sendModeratorMessage(token: string, channelId: string, content: string, logger: { info: (msg: string) => void; warn: (msg: string) => void }): Promise<boolean> {
+  try {
+    const r = await fetch(`https://discord.com/api/v10/channels/${channelId}/messages`, {
+      method: "POST",
+      headers: {
+        "Authorization": `Bot ${token}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ content }),
+    });
+    if (!r.ok) {
+      const text = await r.text();
+      logger.warn(`whispergate: moderator send failed (${r.status}): ${text}`);
+      return false;
+    }
+    logger.info(`whispergate: moderator message sent to channel=${channelId}`);
+    return true;
+  } catch (err) {
+    logger.warn(`whispergate: moderator send error: ${String(err)}`);
+    return false;
+  }
+}
+
 function persistPolicies(api: OpenClawPluginApi): void {
   const filePath = policyState.filePath;
   if (!filePath) throw new Error("policy file path not initialized");
@@ -475,13 +530,22 @@ export default {
         if (preChannelId) {
           ensureTurnOrder(api, preChannelId);
           const from = typeof (e as Record<string, unknown>).from === "string" ? (e as Record<string, unknown>).from as string : "";
-          const humanList = livePre.humanList || livePre.bypassUserIds || [];
-          const isHuman = humanList.includes(from);
-          // Resolve sender's accountId (for bot messages)
-          const senderAccountId = typeof c.accountId === "string" ? c.accountId : undefined;
-          onNewMessage(preChannelId, senderAccountId, isHuman);
-          if (shouldDebugLog(livePre, preChannelId)) {
-            api.logger.info(`whispergate: turn onNewMessage channel=${preChannelId} from=${from} isHuman=${isHuman} accountId=${senderAccountId ?? "unknown"}`);
+
+          // Ignore moderator bot messages — they don't affect turn state
+          const moderatorUserId = getModeratorUserId(livePre);
+          if (moderatorUserId && from === moderatorUserId) {
+            if (shouldDebugLog(livePre, preChannelId)) {
+              api.logger.info(`whispergate: ignoring moderator message in channel=${preChannelId}`);
+            }
+            // Don't call onNewMessage — moderator messages are transparent to turn logic
+          } else {
+            const humanList = livePre.humanList || livePre.bypassUserIds || [];
+            const isHuman = humanList.includes(from);
+            const senderAccountId = typeof c.accountId === "string" ? c.accountId : undefined;
+            onNewMessage(preChannelId, senderAccountId, isHuman);
+            if (shouldDebugLog(livePre, preChannelId)) {
+              api.logger.info(`whispergate: turn onNewMessage channel=${preChannelId} from=${from} isHuman=${isHuman} accountId=${senderAccountId ?? "unknown"}`);
+            }
           }
         }
       } catch (err) {
@@ -730,8 +794,17 @@ export default {
           api.logger.info(
             `whispergate: turn onSpeakerDone channel=${channelId} from=${accountId} next=${nextSpeaker ?? "dormant"} trigger=${trigger}`,
           );
-          // NOTE: if wasNoReply and nextSpeaker is set, the next agent needs
-          // a trigger message to start speaking. See TURN-WAKEUP-PROBLEM.md
+          // Moderator handoff: when current speaker NO_REPLY'd and there's a next speaker,
+          // send a handoff message via the moderator bot to trigger the next agent
+          if (wasNoReply && nextSpeaker && live.moderatorBotToken) {
+            const nextUserId = resolveDiscordUserId(api, nextSpeaker);
+            if (nextUserId) {
+              const handoffMsg = `轮到（<@${nextUserId}>）了，如果没有想说的请直接回复NO_REPLY`;
+              sendModeratorMessage(live.moderatorBotToken, channelId, handoffMsg, api.logger);
+            } else {
+              api.logger.warn(`whispergate: cannot resolve Discord userId for next speaker accountId=${nextSpeaker}`);
+            }
+          }
         }
       } catch (err) {
         api.logger.warn(`whispergate: message_sent hook failed: ${String(err)}`);

plugin/rules.ts

@@ -10,6 +10,8 @@ export type WhisperGateConfig = {
   endSymbols?: string[];
   noReplyProvider: string;
   noReplyModel: string;
+  /** Discord bot token for the moderator bot (used for turn handoff messages) */
+  moderatorBotToken?: string;
 };
 
 export type ChannelPolicy = {