feat(ai): add chart renderer, floating ball hook, and provider updates

- Add ai-chart-renderer for rendering charts in AI responses

- Add use-floating-ball hook for draggable AI assistant widget

- Update ai-assistant-widget, ai-chat-panel, ai-markdown-renderer, ai-provider-selector

- Update use-ai-chat-stream hook and prompt-templates service

src/modules/ai/hooks/use-ai-chat-stream.ts

@@ -1,6 +1,6 @@
 "use client"
 
-import { useState, useCallback, useRef } from "react"
+import { useState, useCallback, useRef, useEffect } from "react"
 import { useTranslations } from "next-intl"
 import type { AiChatMessage } from "../types"
 import {
@@ -11,11 +11,14 @@ import {
   appendTokenToLastAssistant,
 } from "./stream-utils"
 
+const HISTORY_STORAGE_KEY = "ai-chat-history"
+const MAX_HISTORY = 20
+
 /**
  * AI 流式聊天 Hook
  *
  * 通过 SSE 端点消费流式 AI 回复。
- * 支持：逐 token 渲染、停止生成（AbortController）、错误处理。
+ * 支持：逐 token 渲染、停止生成（AbortController）、错误处理、历史持久化恢复。
  */
 type UseAiChatStreamReturn = {
   messages: AiChatMessage[]
@@ -26,13 +29,49 @@ type UseAiChatStreamReturn = {
   clear: () => void
 }
 
+function loadHistory(): AiChatMessage[] {
+  if (typeof window === "undefined") return []
+  try {
+    const raw = localStorage.getItem(HISTORY_STORAGE_KEY)
+    if (!raw) return []
+    const parsed = JSON.parse(raw) as AiChatMessage[]
+    if (!Array.isArray(parsed)) return []
+    // 过滤掉空的 assistant 消息
+    return parsed.filter((m) => m && m.role && typeof m.content === "string")
+  } catch {
+    return []
+  }
+}
+
 export function useAiChatStream(): UseAiChatStreamReturn {
   const t = useTranslations("ai")
-  const [messages, setMessages] = useState<AiChatMessage[]>([])
+  // 懒初始化：从 localStorage 恢复历史
+  const [messages, setMessages] = useState<AiChatMessage[]>(() => loadHistory())
   const [streaming, setStreaming] = useState(false)
   const [error, setError] = useState<string | null>(null)
   const abortControllerRef = useRef<AbortController | null>(null)
 
+  // 持久化（防抖）
+  const persistTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+  useEffect(() => {
+    if (streaming) return
+    if (persistTimerRef.current) clearTimeout(persistTimerRef.current)
+    persistTimerRef.current = setTimeout(() => {
+      try {
+        if (messages.length === 0) {
+          localStorage.removeItem(HISTORY_STORAGE_KEY)
+        } else {
+          localStorage.setItem(HISTORY_STORAGE_KEY, JSON.stringify(messages.slice(-MAX_HISTORY)))
+        }
+      } catch {
+        // ignore
+      }
+    }, 500)
+    return () => {
+      if (persistTimerRef.current) clearTimeout(persistTimerRef.current)
+    }
+  }, [messages, streaming])
+
   const send = useCallback(
     async (
       inputMessages: AiChatMessage[],
@@ -105,6 +144,11 @@ export function useAiChatStream(): UseAiChatStreamReturn {
   const clear = useCallback((): void => {
     setMessages([])
     setError(null)
+    try {
+      localStorage.removeItem(HISTORY_STORAGE_KEY)
+    } catch {
+      // ignore
+    }
   }, [])
 
   return { messages, streaming, error, send, stop, clear }