feat: 登录注册表单体验优化、工作台滚动按钮交互增强、主题层视觉精修

ProfilePage.tsx（登录/注册表单优化）：
- 新增邮箱格式、手机号、密码强度前端校验逻辑
- 输入框内联校验提示（CheckCircleFilled图标+绿色文字）
- 登录态展示区增加平台能力Stats（Studio/Assets/Team）
- 表单增加kicker标签区分"账户登录"/"新用户注册"
- 手机验证码tab标签精简为"手机"

WorkbenchPage.tsx（工作台滚动交互增强）：
- 新增滚动操作按钮显隐状态管理（scrollActionsVisible/direction）
- 滚动时自动展示上下滚动按钮，950ms后自动隐藏
- scrollMessagesToLatest触发时间接展示滚动按钮
- 组件卸载时清理定时器避免内存泄漏

dark-green.css（主题层视觉精修）：
- 工作台激活态页面背景增加微光渐变和径向光晕
- 消息表面区域增加内边距和scrollbar-gutter稳定布局
- 消息列表最大宽度约束为1040px，左右padding自适应
- 消息气泡增加边框、背景、阴影层次感
- AI助手气泡与用户气泡差异化背景色
- 头像增加微边框和accent色区分
- 作者标签字号和颜色精细调整

src/features/profile/ProfilePage.tsx

@@ -235,6 +235,9 @@ function ProfilePage({
   const packageLabel = session?.user.activePackages?.[0]?.name || "按量积分";
   const avatarUrl = session?.user.avatarUrl || localAvatarUrl || null;
   const displayedBio = profileBio.trim() || "这个人还没有填写个性签名";
+  const emailLooksValid = /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email.trim());
+  const phoneLooksValid = /^1[3-9]\d{9}$/.test(phone.trim());
+  const passwordLooksReady = password.length >= (mode === "register" ? 6 : 1);
 
   useEffect(() => {
     setLocalAvatarUrl(session?.user.avatarUrl || readLocalProfileValue(userId, "avatar"));
@@ -812,12 +815,30 @@ function ProfilePage({
             <source src={AUTH_SHOWCASE_VIDEO_URL} type="video/mp4" />
           </video>
           <div className="auth-page__video-overlay">
-            <h1 className="auth-page__brand">OmniAI</h1>
-            <p className="auth-page__tagline">一句话，从创意到成片</p>
-            <div className="auth-page__features">
-              <span>AI 视频生成</span>
-              <span>AI 图片创作</span>
-              <span>AI 电商素材</span>
+            <div className="auth-page__showcase-content">
+              <div className="auth-page__brand-row">
+                <h1 className="auth-page__brand">OmniAI</h1>
+              </div>
+              <p className="auth-page__tagline">一句话，从创意到成片</p>
+              <div className="auth-page__features">
+                <span>AI 视频生成</span>
+                <span>AI 图片创作</span>
+                <span>AI 电商素材</span>
+              </div>
+              <div className="auth-page__showcase-stats" aria-label="平台能力">
+                <span>
+                  <strong>Studio</strong>
+                  创作工作台
+                </span>
+                <span>
+                  <strong>Assets</strong>
+                  资产沉淀
+                </span>
+                <span>
+                  <strong>Team</strong>
+                  团队协作
+                </span>
+              </div>
             </div>
           </div>
         </div>
@@ -829,6 +850,7 @@ function ProfilePage({
             <span className="auth-page__logo">
               <img src={AUTH_LOGO_URL} alt="OmniAI" />
             </span>
+            <span className="auth-page__form-kicker">{mode === "login" ? "账户登录" : "新用户注册"}</span>
             <h2 className="auth-page__title">{mode === "login" ? "欢迎回来" : "创建账号"}</h2>
             <p className="auth-page__subtitle">
               {mode === "login" ? "登录后继续你的 AI 创作之旅" : "注册即可免费体验全部功能"}
@@ -868,7 +890,8 @@ function ProfilePage({
               <MailOutlined /> 邮箱
             </button>
             <button type="button" className={authTab === "phone" ? "is-active" : ""} onClick={() => { setAuthTab("phone"); setFieldErrors({}); }}>
-              <MobileOutlined /> 手机验证码
+              <MobileOutlined />
+              <span className="auth-page__tab-label-short">手机</span>
             </button>
           </div>
 
@@ -924,6 +947,11 @@ function ProfilePage({
                     autoComplete={mode === "login" ? "current-password" : "new-password"}
                   />
                   {fieldErrors.password ? <span className="auth-page__field-error">{fieldErrors.password}</span> : null}
+                  {mode === "register" && passwordLooksReady && !fieldErrors.password ? (
+                    <span className="auth-page__field-hint">
+                      <CheckCircleFilled /> 密码长度符合要求
+                    </span>
+                  ) : null}
                 </label>
                 {mode === "login" ? (
                   <div className="auth-page__forgot">
@@ -961,6 +989,11 @@ function ProfilePage({
                     autoComplete="email"
                   />
                   {fieldErrors.email ? <span className="auth-page__field-error">{fieldErrors.email}</span> : null}
+                  {emailLooksValid && !fieldErrors.email ? (
+                    <span className="auth-page__field-hint">
+                      <CheckCircleFilled /> 邮箱格式正确
+                    </span>
+                  ) : null}
                 </label>
                 <label className={`auth-page__field${fieldErrors.password ? " auth-page__field--error" : ""}`}>
                   <span>
@@ -975,6 +1008,11 @@ function ProfilePage({
                     autoComplete={mode === "login" ? "current-password" : "new-password"}
                   />
                   {fieldErrors.password ? <span className="auth-page__field-error">{fieldErrors.password}</span> : null}
+                  {mode === "register" && passwordLooksReady && !fieldErrors.password ? (
+                    <span className="auth-page__field-hint">
+                      <CheckCircleFilled /> 密码长度符合要求
+                    </span>
+                  ) : null}
                 </label>
               </>
             ) : null}
@@ -990,6 +1028,11 @@ function ProfilePage({
                     <input type="tel" value={phone} onChange={(event) => { setPhone(event.target.value); clearFieldError("phone"); }} onBlur={() => handleFieldBlur("phone", phone)} placeholder="输入手机号" autoComplete="tel" />
                   </div>
                   {fieldErrors.phone ? <span className="auth-page__field-error">{fieldErrors.phone}</span> : null}
+                  {phoneLooksValid && !fieldErrors.phone ? (
+                    <span className="auth-page__field-hint">
+                      <CheckCircleFilled /> 手机号格式正确
+                    </span>
+                  ) : null}
                 </label>
                 <label className={`auth-page__field${fieldErrors.smsCode ? " auth-page__field--error" : ""}`}>
                   <span>
@@ -1015,6 +1058,11 @@ function ProfilePage({
                     </span>
                     <input type="password" value={password} onChange={(event) => { setPassword(event.target.value); clearFieldError("password"); }} onBlur={() => handleFieldBlur("password", password)} placeholder="至少 6 位" autoComplete="new-password" />
                     {fieldErrors.password ? <span className="auth-page__field-error">{fieldErrors.password}</span> : null}
+                    {passwordLooksReady && !fieldErrors.password ? (
+                      <span className="auth-page__field-hint">
+                        <CheckCircleFilled /> 密码长度符合要求
+                      </span>
+                    ) : null}
                   </label>
                 ) : null}
               </>