fix(#709): route Discord threads and approvals

apps/gateway/src/chat/chat.gateway.ts

@@ -639,9 +639,36 @@ export class ChatGateway implements OnGatewayInit, OnGatewayConnection, OnGatewa
    * Creates it if absent — safe to call concurrently since a duplicate insert
    * would fail on the PK constraint and be caught here.
    */
+  @SubscribeMessage('discord:approve')
+  async handleDiscordApproval(
+    @ConnectedSocket() client: Socket,
+    @MessageBody() envelope: DiscordIngressEnvelope,
+  ): Promise<void> {
+    if (!client.data.discordService) return;
+    const ingress = this.resolveDiscordIngress(client, envelope, 'approve');
+    const command = ingress?.content.match(/^\/approve\s+([a-z][\w-]*)$/i)?.[1];
+    const serviceUserId = process.env['DISCORD_SERVICE_USER_ID'];
+    if (!ingress || !command || !serviceUserId) return;
+    const approval = await this.commandExecutor.createApproval(
+      { command, conversationId: ingress.conversationId },
+      {
+        userId: serviceUserId,
+        tenantId: process.env['DISCORD_SERVICE_TENANT_ID'] ?? serviceUserId,
+      },
+    );
+    client.emit('discord:approval', {
+      correlationId: ingress.correlationId,
+      command,
+      success: approval !== null,
+      approvalId: approval?.approvalId,
+      expiresAt: approval?.expiresAt,
+    });
+  }
+
   private resolveDiscordIngress(
     client: Socket,
     envelope: DiscordIngressEnvelope,
+    operation: 'send' | 'approve' = 'send',
   ): DiscordIngressPayload | null {
     const payload = verifyDiscordIngressEnvelope(
       envelope,
@@ -662,7 +689,7 @@ export class ChatGateway implements OnGatewayInit, OnGatewayConnection, OnGatewa
         payload.guildId,
         payload.channelId,
         payload.userId,
-        'send',
+        operation,
       );
       if (!binding) {
         this.logger.warn(`Rejected unpaired Discord ingress from ${client.id}`);

plugins/discord/src/index.ts

@@ -327,15 +327,18 @@ export class DiscordPlugin {
       },
       this.config.serviceToken,
     );
-    this.socket.emit('message', envelope);
+    this.socket.emit(content.startsWith('/approve ') ? 'discord:approve' : 'message', envelope);
   }
 
   private isAllowedMessage(message: DiscordMessage): boolean {
     const guildId = message.guildId;
+    const parentChannelId = 'parentId' in message.channel ? message.channel.parentId : null;
+    // Threads inherit their authorization boundary from their configured parent.
+    const authorizationChannelId = parentChannelId ?? message.channelId;
     return (
       guildId !== null &&
       includesId(this.config.allowedGuildIds, guildId) &&
-      includesId(this.config.allowedChannelIds, message.channelId) &&
+      includesId(this.config.allowedChannelIds, authorizationChannelId) &&
       includesId(this.config.allowedUserIds, message.author.id)
     );
   }