feat(settings): 用户名校验强化、个性签名编辑、字符计数器及提示优化

- 用户名校验改用白名单正则（中英文/数字/下划线/连字符），字符数计法统一
- 简介→个性签名，新增 textarea 可编辑，上限 128 字符
- 用户名+签名各增加实时字符计数器（x/16、x/128）
- API 合并为 PUT /api/settings/profile，一次提交两字段，按变更写入
- Toast 移至 NAV 下方，独立样式，5 秒自动消失
- 移除用户 ID 灰色底色，提示改为「个人资料已更新」
- 纯文本存储 + Go 模板自动转义防 XSS

templates/MetaLab-2026/html/settings/index.html

@@ -3,6 +3,8 @@
 
 {{template "layout/nav.html" .}}
 
+<div class="settings-toast" id="settingsToast"></div>
+
 <div class="settings-layout">
     <aside class="settings-sidebar">
         <nav class="settings-nav">
@@ -36,7 +38,10 @@
             <div class="settings-card-body">
                 <div class="info-row">
                     <span class="info-label">用户名</span>
-                    <span class="info-value">{{.User.Username}}</span>
+                    <span class="info-value">
+                        <input type="text" id="usernameInput" class="settings-text-input" value="{{.User.Username}}" maxlength="16" autocomplete="off">
+                        <span class="char-counter" id="usernameCounter"></span>
+                    </span>
                 </div>
                 <div class="info-row">
                     <span class="info-label">头像</span>
@@ -49,9 +54,10 @@
                     </span>
                 </div>
                 <div class="info-row">
-                    <span class="info-label">简介</span>
-                    <span class="info-value{{if not .User.Bio}} info-muted{{end}}">
-                        {{if .User.Bio}}{{.User.Bio}}{{else}}未填写{{end}}
+                    <span class="info-label">个性签名</span>
+                    <span class="info-value">
+                        <textarea id="bioInput" class="settings-textarea" maxlength="128" placeholder="写一句话介绍自己...">{{.User.Bio}}</textarea>
+                        <div class="char-counter" id="bioCounter"></div>
                     </span>
                 </div>
                 <div class="info-row">
@@ -60,6 +66,9 @@
                         <span class="role-tag role-{{.User.Role}}">{{.RoleName}}</span>
                     </span>
                 </div>
+                <div class="settings-card-footer">
+                    <button id="saveProfileBtn" class="settings-save-btn">保存</button>
+                </div>
             </div>
         </div>
         {{else}}
@@ -72,7 +81,7 @@
             <div class="settings-card-body">
                 <div class="info-row">
                     <span class="info-label">用户 ID</span>
-                    <span class="info-value info-mono">{{.User.ID}}</span>
+                    <span class="info-value">{{.User.ID}}</span>
                 </div>
                 <div class="info-row">
                     <span class="info-label">邮箱</span>
@@ -101,5 +110,111 @@
 {{template "layout/footer.html" .}}
 
 <script src="/static/js/common.js"></script>
+<script>
+(function () {
+    'use strict';
+
+    var usernameInput = document.getElementById('usernameInput');
+    var bioInput = document.getElementById('bioInput');
+    var btn = document.getElementById('saveProfileBtn');
+    if (!usernameInput || !bioInput || !btn) return;
+
+    var toastEl = document.getElementById('settingsToast');
+    var toastTimer = null;
+
+    function showSettingsToast(msg, isError) {
+        if (!toastEl) return;
+        clearTimeout(toastTimer);
+        toastEl.textContent = msg;
+        toastEl.className = 'settings-toast' + (isError ? ' error' : '');
+        void toastEl.offsetWidth;
+        toastEl.classList.add('show');
+        toastTimer = setTimeout(function () {
+            toastEl.classList.remove('show');
+        }, 5000);
+    }
+
+    // ---- 字符计数器 ----
+    var usernameCounter = document.getElementById('usernameCounter');
+    var bioCounterEl = document.getElementById('bioCounter');
+
+    function updateCounters() {
+        if (usernameCounter) {
+            usernameCounter.textContent = usernameInput.value.length + '/16';
+        }
+        if (bioCounterEl) {
+            bioCounterEl.textContent = bioInput.value.length + '/128';
+        }
+    }
+
+    usernameInput.addEventListener('input', updateCounters);
+    bioInput.addEventListener('input', updateCounters);
+    updateCounters();
+
+    // ---- 原始值（用于判断是否变更） ----
+    var origUsername = usernameInput.value.trim();
+    var origBio = bioInput.value;
+
+    // 与后端一致的合法字符集：中文、英文大小写、数字、下划线、连字符
+    var usernameRe = /^[\u4e00-\u9fffa-zA-Z0-9_-]+$/;
+
+    btn.addEventListener('click', function () {
+        var username = usernameInput.value.trim();
+        var bio = bioInput.value;
+
+        // 用户名校验
+        if (!username) {
+            showSettingsToast('用户名不能为空', true);
+            return;
+        }
+        if (username.length > 16) {
+            showSettingsToast('用户名不能超过 16 个字符', true);
+            return;
+        }
+        if (!usernameRe.test(username)) {
+            showSettingsToast('用户名仅支持中英文、数字、下划线、连字符', true);
+            return;
+        }
+
+        // 个性签名校验
+        if (bio.length > 128) {
+            showSettingsToast('个性签名不能超过 128 个字符', true);
+            return;
+        }
+
+        // 无变更判断
+        if (username === origUsername && bio === origBio) {
+            showSettingsToast('内容未变更，无需保存');
+            return;
+        }
+
+        btn.disabled = true;
+        btn.textContent = '保存中...';
+
+        var xhr = new XMLHttpRequest();
+        xhr.open('PUT', '/api/settings/profile', true);
+        xhr.setRequestHeader('Content-Type', 'application/json');
+        xhr.onreadystatechange = function () {
+            if (xhr.readyState !== 4) return;
+            btn.disabled = false;
+            btn.textContent = '保存';
+
+            try {
+                var res = JSON.parse(xhr.responseText);
+                if (res.success) {
+                    showSettingsToast(res.message || '个人资料已更新');
+                    origUsername = username;
+                    origBio = bio;
+                } else {
+                    showSettingsToast(res.message || '保存失败', true);
+                }
+            } catch (e) {
+                showSettingsToast('保存失败', true);
+            }
+        };
+        xhr.send(JSON.stringify({ username: username, bio: bio }));
+    });
+})();
+</script>
 </body>
 </html>