feat(context): 添加上下文压缩 API 和 UI 组件

Server API:
- 扩展 Agent Adapter 接口添加压缩相关方法
- 新增 context.ts 路由 (GET /sessions/:id/context, POST /sessions/:id/compress)
- 扩展 config.ts 添加摘要模型配置接口 (GET/PUT /config/summary)

UI 组件:
- 新增 ContextUsage 组件显示上下文使用情况
- 扩展 ConfigPanel 添加摘要模型配置区域
- 添加 API 客户端方法和类型定义

Web 集成:
- 在 Chat 页面头部集成 ContextUsage 紧凑模式显示

packages/ui/src/api/client.ts

@@ -45,6 +45,11 @@ import type {
   CustomProviderDefinition,
   ProviderConfig,
   ConnectionTestResult,
+  // Context & Summary types
+  ContextUsageInfo,
+  CompressionResult,
+  SummaryConfigInfo,
+  SummaryConfigInput,
 } from './types.js';
 
 // Re-export types
@@ -113,6 +118,14 @@ export type {
   CustomProviderDefinition,
   ProviderConfig,
   ConnectionTestResult,
+  // Context compression types
+  TokenUsage,
+  ContextUsageInfo,
+  CompressionStatus,
+  CompressionType,
+  CompressionResult,
+  SummaryConfigInfo,
+  SummaryConfigInput,
 } from './types.js';
 
 // API Configuration
@@ -936,3 +949,54 @@ export async function deleteProviderModel(
 }> {
   return request('DELETE', `/providers/${encodeURIComponent(providerId)}/models/${encodeURIComponent(modelId)}`);
 }
+
+// ============ Context Compression API ============
+
+/**
+ * 获取会话上下文使用情况
+ */
+export async function getContextUsage(sessionId: string): Promise<{
+  success: boolean;
+  data?: ContextUsageInfo;
+  error?: string;
+}> {
+  return request('GET', `/sessions/${encodeURIComponent(sessionId)}/context`);
+}
+
+/**
+ * 触发上下文压缩
+ */
+export async function compressContext(
+  sessionId: string,
+  options?: { force?: boolean }
+): Promise<{
+  success: boolean;
+  data?: CompressionResult;
+  error?: string;
+}> {
+  return request('POST', `/sessions/${encodeURIComponent(sessionId)}/compress`, options || {});
+}
+
+/**
+ * 获取摘要模型配置
+ */
+export async function getSummaryConfig(): Promise<{
+  success: boolean;
+  data?: SummaryConfigInfo;
+  error?: string;
+}> {
+  return request('GET', '/config/summary');
+}
+
+/**
+ * 更新摘要模型配置
+ */
+export async function updateSummaryConfig(
+  config: SummaryConfigInput
+): Promise<{
+  success: boolean;
+  data?: SummaryConfigInfo;
+  error?: string;
+}> {
+  return request('PUT', '/config/summary', config);
+}