✨ feat(ai): 发布全新 AI Copilot 助手面板与工作区智能打通

- 核心架构：新增独立 AI 会话中枢，集成主流大模型生态（含私有部署中继版）的无感衔接发问
- 智能诊断：打破信息孤岛，大模型可通过关联工作区实时数据表 DDL 和错误栈，充当专属 DBA 排错及代码编写
- 视觉与多模态：支持极简发图读图交互体验，智能补全模型所需的缺省预警 Prompt，并兼容不规范中转端点图文并茂
- UI 与性能：重构聊天浮层挂靠逻辑与渲染阻断，应对长时间巨量问答引发的卡段内存泄漏，会话自动保存归档

frontend/src/types.ts

@@ -190,6 +190,12 @@ export type AIProviderType = 'openai' | 'anthropic' | 'gemini' | 'custom';
 export type AISafetyLevel = 'readonly' | 'readwrite' | 'full';
 export type AIContextLevel = 'schema_only' | 'with_samples' | 'with_results';
 
+export interface AIContextItem {
+  dbName: string;
+  tableName: string;
+  ddl: string;
+}
+
 export interface AIProviderConfig {
   id: string;
   type: AIProviderType;
@@ -204,12 +210,31 @@ export interface AIProviderConfig {
   temperature: number;
 }
 
+export interface AIToolCall {
+  id: string;
+  type: string;
+  function: {
+    name: string;
+    arguments: string;
+  };
+}
+
+export type ChatPhase = 'idle' | 'connecting' | 'thinking' | 'generating' | 'tool_calling';
+
 export interface AIChatMessage {
   id: string;
-  role: 'user' | 'assistant' | 'system';
+  role: 'user' | 'assistant' | 'system' | 'tool';
+  phase?: ChatPhase;
   content: string;
+  thinking?: string;
   timestamp: number;
   loading?: boolean;
+  images?: string[]; // base64 encoded images with data URI prefix
+  tool_calls?: AIToolCall[];
+  tool_call_id?: string;
+  tool_name?: string; // used for UI display
+  rawError?: string; // 存储未清洗的原始错误信息，用于用户复制排查
+  success?: boolean; // 标记探针执行是否成功
 }
 
 export interface AISafetyResult {