feat(site): 对齐参考站点UI与交互调整

- 页脚：响应耗时文字统一为「响应耗时 XXXms」，版本链接改为 GitHub 官方仓库，默认 ICP 备案号设置为粤ICP备2025450093号
- 顶部栏：恢复主题切换按钮与语言按钮（语言暂为占位提示），放置于用户区左侧
- 主题：修复首屏内联脚本默认主题白名单校验，避免 localStorage 中残留的 light/dark/System 等非法值生效，首屏默认改为 ClassicLight（仅允许 ClassicLight/ModernLight）
- 登录页：在密码输入框下方恢复「忘记密码？」入口，新增配套的找回密码引导页 /forgot-password
- 默认配置：system-settings 兜底记录与 SYSTEM_SETTINGS_DEFAULTS 新增 icpNumber 默认值

nuxt.config.ts

@@ -192,7 +192,11 @@ export default defineNuxtConfig({
         { name: 'theme-color', content: '#111111' },
         {
           name: 'x-default-theme',
-          content: process.env.NUXT_PUBLIC_DEFAULT_THEME || 'System'
+          content: process.env.NUXT_PUBLIC_DEFAULT_THEME || 'ClassicLight'
+        },
+        {
+          name: 'x-enabled-themes',
+          content: process.env.NUXT_PUBLIC_ENABLED_THEMES || 'ClassicLight,ModernLight'
         },
         { name: 'apple-mobile-web-app-capable', content: 'yes' },
         { name: 'apple-mobile-web-app-status-bar-style', content: 'black-translucent' },
@@ -206,18 +210,28 @@ export default defineNuxtConfig({
           tagPosition: 'head',
           children: [
             `(function(){try{`,
-            `  var k='voicehub:theme', d=document, r=d.documentElement, s=null, eff=null;`,
-            `  try{s=localStorage.getItem(k)}catch(e){s=null}`,
-            `  if(!s){`,
-            `    try{`,
-            `      var meta=document.querySelector('meta[name="x-default-theme"]');`,
-            `      if(meta && meta.content){s=meta.content}`,
-            `    }catch(e){s=null}`,
-            `    if(!s){s='System'}`,
+            `  var k='voicehub:theme', d=document, r=d.documentElement, s=null, eff=null, def=null, list=[];`,
+            `  try{`,
+            `    var mt=d.querySelector('meta[name="x-enabled-themes"]');`,
+            `    if(mt && mt.content){list=String(mt.content).split(',').map(function(x){return x.replace(/^\\s+|\\s+$/g,'')}).filter(Boolean)}`,
+            `  }catch(e){list=[]}`,
+            `  try{`,
+            `    var md=d.querySelector('meta[name="x-default-theme"]');`,
+            `    if(md && md.content){def=md.content}`,
+            `  }catch(e){def=null}`,
+            `  if(!def){def='ClassicLight'}`,
+            `  if(list.length===0){list=['ClassicLight','ModernLight']}`,
+            `  function valid(t){`,
+            `    if(list.indexOf(t)!==-1){return t}`,
+            `    if(list.indexOf(def)!==-1){return def}`,
+            `    return list[0]`,
             `  }`,
-            `  if(s==='System'||s==='system'){eff=window.matchMedia('(prefers-color-scheme: dark)').matches?'dark':'light'}`,
+            `  try{s=localStorage.getItem(k)}catch(e){s=null}`,
+            `  if(!s){s=def}`,
+            `  else{s=valid(s)}`,
+            `  if(typeof s==='string' && (s==='System'||s==='system')){eff=window.matchMedia('(prefers-color-scheme: dark)').matches?'dark':'light'}`,
             `  else if(typeof s==='string'){eff=s.endsWith('Dark')||s==='dark'?'dark':(s.endsWith('Light')||s==='light'?'light':s)}`,
-            `  else{eff='dark'}`,
+            `  else{eff='light'}`,
             `  r.setAttribute('data-theme', (typeof s==='string'?s:eff));`,
             `  if(eff==='dark'){r.classList.add('dark'); r.classList.remove('light'); r.style.colorScheme='dark'}`,
             `  else if(eff==='light'){r.classList.add('light'); r.classList.remove('dark'); r.style.colorScheme='light'}`,