feat(server): 添加统一命令系统 API

- 新增 /api/commands 路由，支持列出、查询、执行和搜索命令
- Server 通过动态导入 Core 的 CommandRegistry 和 CommandExecutor
- CLI、Web、Desktop 客户端均可通过 REST API 访问斜杠命令
- 支持三层命令优先级: project > user > builtin

packages/cli/src/client/api.ts

@@ -46,6 +46,37 @@ export interface HealthStatus {
   };
 }
 
+// ============ Command 相关 ============
+
+export interface CommandInfo {
+  name: string;
+  description?: string;
+  agent?: string;
+  model?: string;
+  subtask?: boolean;
+  source: string;
+  hasTemplate: boolean;
+}
+
+export interface CommandSearchResult {
+  name: string;
+  description?: string;
+  source: string;
+  score: number;
+}
+
+export interface CommandExecuteResult {
+  prompt: string;
+  agent?: string;
+  model?: string;
+  subtask?: boolean;
+}
+
+export interface CommandListResponse {
+  commands: Array<{ name: string; description?: string; source: string }>;
+  stats: { total: number; bySource: Record<string, number> };
+}
+
 /**
  * API Client 类
  */
@@ -180,6 +211,41 @@ export class APIClient {
       ? `${sseUrl}?token=${encodeURIComponent(this.token)}`
       : sseUrl;
   }
+
+  // ============================================================================
+  // Commands
+  // ============================================================================
+
+  async listCommands(): Promise<{ success: boolean; data: CommandListResponse }> {
+    return this.request('GET', '/api/commands');
+  }
+
+  async getCommand(name: string): Promise<{ success: boolean; data: CommandInfo }> {
+    return this.request('GET', `/api/commands/${encodeURIComponent(name)}`);
+  }
+
+  async executeCommand(
+    name: string,
+    args: string = ''
+  ): Promise<{ success: boolean; data?: CommandExecuteResult; error?: string }> {
+    return this.request('POST', `/api/commands/${encodeURIComponent(name)}/execute`, {
+      arguments: args,
+    });
+  }
+
+  async searchCommands(
+    query: string,
+    limit: number = 10
+  ): Promise<{ success: boolean; data: CommandSearchResult[] }> {
+    return this.request('POST', '/api/commands/search', { query, limit });
+  }
+
+  async reloadCommands(): Promise<{
+    success: boolean;
+    data: { message: string; stats: { total: number; bySource: Record<string, number> } };
+  }> {
+    return this.request('POST', '/api/commands/reload');
+  }
 }
 
 /**