feat: 统一 AI 设计 Workspace 与生成任务链路

需求：以设计项目组织固定设计 Agent 对话、方向确认和图片视频任务。

实现：新增 Works Square 云端适配与开发态本地适配，统一 Host API、Quote 确认、任务轮询及私有媒体 Range 代理。

electron/image-workspace/module.ts

@@ -0,0 +1,35 @@
+import type {
+  DesignCapabilities,
+  DesignConfirmGenerationInput,
+  DesignCreateWorkspaceInput,
+  DesignGenerationTask,
+  DesignRenameWorkspaceInput,
+  DesignSubmitMessageInput,
+  DesignWorkspace,
+  DesignWorkspaceBootstrap,
+} from '../../shared/image-workspace';
+
+export class DesignWorkspaceModuleError extends Error {
+  readonly status: number;
+  readonly code: string;
+
+  constructor(status: number, code: string, message: string) {
+    super(message);
+    this.name = 'DesignWorkspaceModuleError';
+    this.status = status;
+    this.code = code;
+  }
+}
+
+export interface DesignWorkspaceModule {
+  bootstrap(): Promise<DesignWorkspaceBootstrap>;
+  getCapabilities(): Promise<DesignCapabilities>;
+  createWorkspace(input: DesignCreateWorkspaceInput): Promise<DesignWorkspace>;
+  renameWorkspace(input: DesignRenameWorkspaceInput): Promise<DesignWorkspace>;
+  getWorkspace(workspaceId: string): Promise<DesignWorkspace>;
+  submitMessage(input: DesignSubmitMessageInput): Promise<DesignWorkspace>;
+  confirmGeneration(input: DesignConfirmGenerationInput): Promise<DesignWorkspace>;
+  listTasks(workspaceId: string): Promise<DesignGenerationTask[]>;
+  openAssetContent(workspaceId: string, assetId: string, range?: string): Promise<Response>;
+  reset?(): Promise<DesignWorkspaceBootstrap>;
+}