refactor(chat): align chat header and input bar with Dart source

src/app/chat/components/chat-input-bar.tsx

@@ -4,25 +4,28 @@
  *
  * 原始 Dart: lib/ui/chat/widgets/chat_input_bar.dart（121 行）
  *
- * 组成（从左到右）：
- *   - ChatMoreButton（⊞）：展开更多选项（图片/语音/功能）
- *   - ChatInputTextField：文本输入
- *   - ChatSendButton（↑）：发送
- *
- * 状态管理（自包含）：
+ * 状态：
  *   - input：受控文本
- *   - focused：是否聚焦（视觉状态）
- *   - hasContent：是否有内容（决定发送按钮启用）
+ *   - isFocused：是否聚焦（控制外层 pink-bg / box-shadow / padding-top）
+ *   - hasContent：是否有 trim 内容（决定发送按钮是否启用）
+ *
+ * 容器层次（与 Dart 一致）：
+ *   - 外层 `.bar`：focused 时 `padding-top: md` + 粉色背景 + 阴影
+ *   - 内层 `.row`：白底 + `border-radius: 32` + focused 时 accent 边框
+ *   - Row：[ChatInputTextField (Expanded), ChatSendButton]
+ *
+ * 行为：
+ *   - send 后清空 input + 保持 textarea 焦点（与 Dart `_focusNode.requestFocus()` 一致）
+ *
+ * 注意：Dart 源里的 `ImageUploadButton` 已被注释（`// const ImageUploadButton()`），
+ *       `ChatMoreButton` / `FunctionButtonBar` 不存在于 Dart 源；本组件仅保留与 Dart 一致的部分。
  */
-import { useState } from "react";
+import { useRef, useState } from "react";
 
 import { useChatDispatch } from "@/stores/chat/chat-context";
 
 import { ChatInputTextField } from "./chat-input-text-field";
-import { ChatMoreButton } from "./chat-more-button";
 import { ChatSendButton } from "./chat-send-button";
-import { FunctionButtonBar } from "./function-button-bar";
-import { ImageUploadButton } from "./image-upload-button";
 import styles from "./chat-input-bar.module.css";
 
 export interface ChatInputBarProps {
@@ -32,8 +35,8 @@ export interface ChatInputBarProps {
 export function ChatInputBar({ disabled = false }: ChatInputBarProps) {
   const dispatch = useChatDispatch();
   const [input, setInput] = useState("");
-  const [focused, setFocused] = useState(false);
-  const [showFunctions, setShowFunctions] = useState(false);
+  const [isFocused, setIsFocused] = useState(false);
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
 
   const hasContent = input.trim().length > 0;
 
@@ -41,45 +44,24 @@ export function ChatInputBar({ disabled = false }: ChatInputBarProps) {
     if (!hasContent) return;
     dispatch({ type: "ChatSendMessage", content: input });
     setInput("");
+    textareaRef.current?.focus();
   };
 
   return (
-    <div className={styles.bar}>
-      {showFunctions && (
-        <FunctionButtonBar
-          items={[
-            {
-              key: "image",
-              icon: "🖼",
-              label: "Image",
-              // ImageUploadButton 内部已管理 sheet；FunctionButtonBar 仅触发
-              onClick: () => {
-                /* 触发：ImageUploadButton 已在 ChatInputBar 中渲染 */
-              },
-            },
-            { key: "restart", icon: "↻", label: "Restart" },
-            { key: "history", icon: "⏱", label: "History" },
-            { key: "call", icon: "📞", label: "Call" },
-          ]}
+    <div className={`${styles.bar} ${isFocused ? styles.barFocused : ""}`}>
+      <div className={`${styles.row} ${isFocused ? styles.rowFocused : ""}`}>
+        <ChatInputTextField
+          ref={textareaRef}
+          value={input}
+          onChange={setInput}
+          onSubmit={handleSend}
+          onFocusChange={setIsFocused}
+          disabled={disabled}
+        />
+        <ChatSendButton
+          disabled={!hasContent || disabled}
+          onClick={handleSend}
         />
-      )}
-
-      <div className={`${styles.row} ${focused ? styles.rowFocused : ""}`}>
-        <ImageUploadButton disabled={disabled} />
-        <ChatMoreButton onClick={() => setShowFunctions((v) => !v)} />
-        <div
-          className={styles.textFieldWrap}
-          onFocus={() => setFocused(true)}
-          onBlur={() => setFocused(false)}
-        >
-          <ChatInputTextField
-            value={input}
-            onChange={setInput}
-            onSubmit={handleSend}
-            disabled={disabled}
-          />
-        </div>
-        <ChatSendButton disabled={!hasContent || disabled} onClick={handleSend} />
       </div>
     </div>
   );