feat: Add CLI session pause and resume functionality with UI integration

ccw/src/core/routes/cli-sessions-routes.ts

@@ -444,5 +444,59 @@ export async function handleCliSessionsRoutes(ctx: RouteContext): Promise<boolea
     return true;
   }
 
+  // POST /api/cli-sessions/:sessionKey/pause
+  const pauseMatch = pathname.match(/^\/api\/cli-sessions\/([^/]+)\/pause$/);
+  if (pauseMatch && req.method === 'POST') {
+    const sessionKey = decodeURIComponent(pauseMatch[1]);
+    try {
+      manager.pauseSession(sessionKey);
+      appendCliSessionAudit({
+        type: 'session_paused',
+        timestamp: new Date().toISOString(),
+        projectRoot,
+        sessionKey,
+        ...clientInfo(req),
+      });
+      res.writeHead(200, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify({ success: true }));
+    } catch (err) {
+      const message = (err as Error).message;
+      if (message.includes('not found')) {
+        res.writeHead(404, { 'Content-Type': 'application/json' });
+      } else {
+        res.writeHead(400, { 'Content-Type': 'application/json' });
+      }
+      res.end(JSON.stringify({ error: message }));
+    }
+    return true;
+  }
+
+  // POST /api/cli-sessions/:sessionKey/resume
+  const resumeMatch = pathname.match(/^\/api\/cli-sessions\/([^/]+)\/resume$/);
+  if (resumeMatch && req.method === 'POST') {
+    const sessionKey = decodeURIComponent(resumeMatch[1]);
+    try {
+      manager.resumeSession(sessionKey);
+      appendCliSessionAudit({
+        type: 'session_resumed',
+        timestamp: new Date().toISOString(),
+        projectRoot,
+        sessionKey,
+        ...clientInfo(req),
+      });
+      res.writeHead(200, { 'Content-Type': 'application/json' });
+      res.end(JSON.stringify({ success: true }));
+    } catch (err) {
+      const message = (err as Error).message;
+      if (message.includes('not found')) {
+        res.writeHead(404, { 'Content-Type': 'application/json' });
+      } else {
+        res.writeHead(400, { 'Content-Type': 'application/json' });
+      }
+      res.end(JSON.stringify({ error: message }));
+    }
+    return true;
+  }
+
   return false;
 }

ccw/src/core/services/cli-session-audit.ts

@@ -4,6 +4,8 @@ import path from 'path';
 export type CliSessionAuditEventType =
   | 'session_created'
   | 'session_closed'
+  | 'session_paused'
+  | 'session_resumed'
   | 'session_send'
   | 'session_execute'
   | 'session_resize'

ccw/src/core/services/cli-session-manager.ts

@@ -23,6 +23,7 @@ export interface CliSession {
   resumeKey?: string;
   createdAt: string;
   updatedAt: string;
+  isPaused: boolean;
 }
 
 export interface CreateCliSessionOptions {
@@ -57,6 +58,7 @@ interface CliSessionInternal extends CliSession {
   buffer: string[];
   bufferBytes: number;
   lastActivityAt: number;
+  isPaused: boolean;
 }
 
 function nowIso(): string {
@@ -227,6 +229,7 @@ export class CliSessionManager {
       buffer: [],
       bufferBytes: 0,
       lastActivityAt: Date.now(),
+      isPaused: false,
     };
 
     pty.onData((data) => {
@@ -318,6 +321,57 @@ export class CliSessionManager {
     }
   }
 
+  pauseSession(sessionKey: string): void {
+    const session = this.sessions.get(sessionKey);
+    if (!session) {
+      throw new Error(`Session not found: ${sessionKey}`);
+    }
+    if (session.isPaused) {
+      throw new Error(`Session already paused: ${sessionKey}`);
+    }
+    const pid = session.pty.pid;
+    if (pid === undefined) {
+      throw new Error(`Session PTY has no PID: ${sessionKey}`);
+    }
+    try {
+      process.kill(pid, 'SIGSTOP');
+      session.isPaused = true;
+      session.updatedAt = nowIso();
+      broadcastToClients({
+        type: 'CLI_SESSION_PAUSED',
+        payload: { sessionKey, timestamp: nowIso() }
+      });
+    } catch (err) {
+      throw new Error(`Failed to pause session ${sessionKey}: ${(err as Error).message}`);
+    }
+  }
+
+  resumeSession(sessionKey: string): void {
+    const session = this.sessions.get(sessionKey);
+    if (!session) {
+      throw new Error(`Session not found: ${sessionKey}`);
+    }
+    if (!session.isPaused) {
+      throw new Error(`Session is not paused: ${sessionKey}`);
+    }
+    const pid = session.pty.pid;
+    if (pid === undefined) {
+      throw new Error(`Session PTY has no PID: ${sessionKey}`);
+    }
+    try {
+      process.kill(pid, 'SIGCONT');
+      session.isPaused = false;
+      session.updatedAt = nowIso();
+      session.lastActivityAt = Date.now();
+      broadcastToClients({
+        type: 'CLI_SESSION_RESUMED',
+        payload: { sessionKey, timestamp: nowIso() }
+      });
+    } catch (err) {
+      throw new Error(`Failed to resume session ${sessionKey}: ${(err as Error).message}`);
+    }
+  }
+
   execute(sessionKey: string, options: ExecuteInCliSessionOptions): { executionId: string; command: string } {
     const session = this.sessions.get(sessionKey);
     if (!session) {