fix: 全面修复审计问题并优化系统提示词

**崩溃/挂死修复 (5):**
- 统一 TrayManager.isQuitting 变量，修复 Cmd+Q 无法退出
- useAgentStream 闭包过期快照 → 每次 getState()
- Agnes chatStream 添加 AbortSignal.timeout
- SSE JSON.parse 添加 try-catch 保护
- Orchestrator setTools 污染 → save/restore 模式

**功能修复 (14):**
- 上下文压缩实现 (每5轮 COMPRESSING 状态)
- 修复 requestId 硬编码空串
- ConfigService.set() 保留已有 category
- MemoryManager 新增 working 类型搜索
- PromptInjectionDefender 补全 sanitize()
- Ollama: 补全 dynamicReminders + reasoningContent
- openai-format: 所有 assistant 消息保留 reasoningContent
- SSE: finish_reason 时提前 flush tool_calls
- DeepSeek thinking effort 映射注释
- Ollama done_reason load→stop
- RateLimitHook >= 边界修复
- WorkspaceService isValid 首次启动修复
- sessions:archive IPC handler
- 托盘/窗口图标路径生产环境修复

**系统提示词优化:**
- SOUL.md 存在时不显示兜底身份，原文放最前
- 兜底身份改为中文 (MetonaAI 自身描述)
- 用户文本在前，附件内容在后

**文件上传:**
- 非图片文件不再 base64 编码，保留 JSON 结构
- 用户文本优先于文件内容

**UI 修复:**
- 首页 Logo 路径修复 (public/ + 相对路径)
- TokenUsage contextWindow 动态计算 (Provider 感知)
- 切换 Provider 同步 contextWindow
- 托盘图标始终显示 Logo (状态由右键菜单展示)

electron/services/mcp-manager.service.ts

@@ -14,6 +14,7 @@
 
 import { Client } from '@modelcontextprotocol/sdk/client/index.js';
 import { StdioClientTransport } from '@modelcontextprotocol/sdk/client/stdio.js';
+import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js';
 import type { Tool } from '@modelcontextprotocol/sdk/types.js';
 import { nanoid } from 'nanoid';
 import type Database from 'better-sqlite3';
@@ -170,13 +171,19 @@ export class MCPManager {
           command: config.command,
           args,
         });
+      } else if (config.transport === 'sse' && config.url) {
+        // SSE 模式（远程 HTTP）
+        transport = new SSEClientTransport(new URL(config.url));
       } else {
-        throw new Error(`Unsupported transport: ${config.transport}. Only 'stdio' is currently supported.`);
+        throw new Error(
+          `Unsupported transport "${config.transport}". ` +
+          `'stdio' requires 'command', 'sse' requires 'url'.`,
+        );
       }
 
       const client = new Client(
         { name: 'metona-ai-desktop', version: '1.0.0' },
-        { capabilities: { tools: {} } },
+        { capabilities: {} },
       );
 
       await client.connect(transport);