feat: refresh shared chat and server workflows

etc/servers/work-server/src/services/chat-service.ts

@@ -45,6 +45,7 @@ import {
 } from './notification-message-service.js';
 import { extractChatMessageParts, type ChatMessagePart } from './chat-message-parts.js';
 import { resolveMainProjectRoot } from './main-project-root-service.js';
+import { isRuntimeDraining, trackWebSocketConnectionClosed, trackWebSocketConnectionOpened } from './runtime-drain-service.js';
 import {
   findLatestPlanItem,
   findPlanItemByPreviewUrl,
@@ -322,6 +323,14 @@ export function getActiveChatService() {
   return activeChatService;
 }
 
+type ChatServiceRuntimeSnapshot = {
+  activeRequestCount: number;
+  queuedRequestCount: number;
+  connectedSessionCount: number;
+  activeSocketCount: number;
+  canAcceptNewRequests: boolean;
+};
+
 function getSessionSocketReadyState(session: ChatSessionState) {
   for (const socket of session.sockets) {
     if (socket.readyState === SOCKET_READY_STATE_OPEN) {
@@ -4362,6 +4371,38 @@ export class ChatService {
     };
   }
 
+  getRuntimeSnapshot(): ChatServiceRuntimeSnapshot {
+    let activeRequestCount = 0;
+    let queuedRequestCount = 0;
+    let activeSocketCount = 0;
+    let connectedSessionCount = 0;
+
+    for (const session of this.sessions.values()) {
+      activeRequestCount += session.activeRequestCount;
+      queuedRequestCount += session.queue.length;
+
+      let sessionHasOpenSocket = false;
+      for (const socket of session.sockets) {
+        if (socket.readyState === SOCKET_READY_STATE_OPEN) {
+          activeSocketCount += 1;
+          sessionHasOpenSocket = true;
+        }
+      }
+
+      if (sessionHasOpenSocket) {
+        connectedSessionCount += 1;
+      }
+    }
+
+    return {
+      activeRequestCount,
+      queuedRequestCount,
+      connectedSessionCount,
+      activeSocketCount,
+      canAcceptNewRequests: !isRuntimeDraining(),
+    };
+  }
+
   close() {
     activeRuntimeController = null;
     if (activeChatService === this) {
@@ -5267,6 +5308,7 @@ export class ChatService {
     session.sockets.add(socket);
     session.lastSeenAt = Date.now();
     this.clientStates.set(socket, session);
+    trackWebSocketConnectionOpened();
 
     socket.on('message', (raw: RawData) => {
       this.handleMessage(socket, raw);
@@ -5275,12 +5317,14 @@ export class ChatService {
     socket.on('close', () => {
       this.clientStates.delete(socket);
       session.sockets.delete(socket);
+      trackWebSocketConnectionClosed();
     });
 
     socket.on('error', (error: Error) => {
       this.logger.error(error, 'chat websocket error');
       this.clientStates.delete(socket);
       session.sockets.delete(socket);
+      trackWebSocketConnectionClosed();
     });
 
     await this.initializeSession(session);
@@ -5640,6 +5684,16 @@ export class ChatService {
       return null;
     }
 
+    if (isRuntimeDraining()) {
+      this.sendToSession(state, {
+        type: 'chat:error',
+        payload: {
+          message: '현재 서버가 배포 전환 중이라 새 AI 요청을 받지 않습니다. 잠시 후 다시 시도해 주세요.',
+        },
+      });
+      return null;
+    }
+
     if (contextOverride) {
       const mergedContext = {
         ...(state.context ?? {