fix(chat): replace Android keyboard workaround

src/app/chat/components/chat-input-bar.module.css

@@ -1,20 +1,13 @@
 /* ChatInputBar 输入栏容器样式（与 Dart chat_input_bar.dart 对齐） */
 
-/* 键盘适配：
- *   --chat-input-lift 是小米 Android + Facebook IAB 的专用抬升值。
- *   --chat-input-lift-effective 只有目标设备标记存在时才读取抬升值。
- *   --app-safe-bottom 处理小米全面屏手势条 / iPhone home indicator。
- *   正常浏览器中 --chat-input-lift 为 0，因此无视觉副作用。 */
-:global(html[data-keyboard-adapt="android-facebook-target"]) {
-  --chat-input-lift-effective: var(--chat-input-lift, 0px);
-}
+/* 键盘适配：--chat-input-lift 仅写入当前聊天输入栏。 */
 
 .bar {
   flex: 0 0 auto;
   padding: 0
     calc(var(--chat-inline-padding, 16px) + var(--app-safe-right, 0px))
     calc(
-      var(--spacing-lg, 16px) + var(--chat-input-lift-effective, 0px) +
+      var(--spacing-lg, 16px) + var(--chat-input-lift, 0px) +
         var(--app-safe-bottom, 0px)
     )
     calc(var(--chat-inline-padding, 16px) + var(--app-safe-left, 0px));

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

@@ -2,9 +2,9 @@
 import { useRef, useState } from "react";
 
 import { useChatDispatch } from "@/stores/chat/chat-context";
-import { useKeyboardHeight } from "@/hooks";
 import { Logger } from "@/utils/logger";
 
+import { useChatKeyboardAvoidance } from "../hooks/use-chat-keyboard-avoidance";
 import { ChatInputTextField } from "./chat-input-text-field";
 import { ChatSendButton } from "./chat-send-button";
 import styles from "./chat-input-bar.module.css";
@@ -20,13 +20,14 @@ export function ChatInputBar({ disabled = false }: ChatInputBarProps) {
   const dispatch = useChatDispatch();
   const [input, setInput] = useState("");
   const [isFocused, setIsFocused] = useState(false);
+  const barRef = useRef<HTMLDivElement>(null);
   const textareaRef = useRef<HTMLTextAreaElement>(null);
   const lastPointerSendAtRef = useRef(0);
 
   const hasContent = input.trim().length > 0;
 
-  useKeyboardHeight({
-    targetRef: textareaRef,
+  useChatKeyboardAvoidance({
+    containerRef: barRef,
     active: isFocused,
   });
 
@@ -68,7 +69,10 @@ export function ChatInputBar({ disabled = false }: ChatInputBarProps) {
   };
 
   return (
-    <div className={`${styles.bar} ${isFocused ? styles.barFocused : ""}`}>
+    <div
+      ref={barRef}
+      className={`${styles.bar} ${isFocused ? styles.barFocused : ""}`}
+    >
       <div className={`${styles.row} ${isFocused ? styles.rowFocused : ""}`}>
         <ChatInputTextField
           ref={textareaRef}