UI 全面重设计: 明亮画廊风格 + 剧集合并显示

## 色彩体系重构
- tailwind.config.js: sand/ink 全新色阶 + shadow 阴影预设
- index.css: 全组件系统重写 (card/input/btn/badge/table)

## 核心页面重写
- LoginPage: 纯白卡片 + 品牌光晕 + Framer Motion 入场动画
- HomePage: Billboard 推荐位 + 剧集卡片联动媒体库
- Layout: 白色侧边栏 + 路由过渡动画
- MediaCard: 新增 linkTo prop, 悬停浮层优化

## 剧集合并显示
- LibraryPage: 使用 groupSeries 合并剧集, 分季选集详情
- 首页剧集卡片自动链接到媒体库详情

## 全量类名迁移 (43 文件)
- text-slate-* -> text-ink-*/text-sand-*
- text-primary-* -> text-brand-*
- text-white -> text-ink-600
- bg/border-slate-* -> bg/border-sand-*
- 500+ 深色硬编码类名清零

web/src/pages/StoragePage.tsx

@@ -33,18 +33,18 @@ export function StoragePage() {
       .finally(() => setLoading(false))
   }, [])
 
-  if (loading) return <p className="text-slate-500">加载中…</p>
-  if (!data) return <p className="text-slate-500">无法获取存储数据</p>
+  if (loading) return <p className="text-sand-500">加载中…</p>
+  if (!data) return <p className="text-sand-500">无法获取存储数据</p>
 
   const totalBytes = data.total_bytes || 1
 
   return (
     <div className="space-y-8">
       <header className="flex items-center gap-3">
-        <HardDrive className="h-6 w-6 text-primary-400" />
+        <HardDrive className="h-6 w-6 text-brand-500" />
         <div>
-          <h1 className="font-display text-3xl font-bold text-white">存储</h1>
-          <p className="text-sm text-slate-400">
+          <h1 className="font-display text-3xl font-bold text-ink-600">存储</h1>
+          <p className="text-sm text-ink-50">
             按媒体库和容器格式统计的磁盘占用,数据来自数据库快照(无须实时扫描磁盘)。
           </p>
         </div>
@@ -57,10 +57,10 @@ export function StoragePage() {
       </section>
 
       <section className="space-y-3">
-        <h2 className="font-display text-xl font-semibold text-white">按媒体库</h2>
+        <h2 className="font-display text-xl font-semibold text-ink-600">按媒体库</h2>
         <div className="glass-panel">
           <table className="w-full text-left text-sm">
-            <thead className="text-xs uppercase tracking-wider text-slate-500">
+            <thead className="text-xs uppercase tracking-wider text-sand-500">
               <tr>
                 <th className="py-2">名称</th>
                 <th>类型</th>
@@ -74,10 +74,10 @@ export function StoragePage() {
                 const pct = (l.total_bytes / totalBytes) * 100
                 return (
                   <tr key={l.library_id} className="border-t border-white/5">
-                    <td className="py-2 text-white">{l.name}</td>
-                    <td className="text-slate-300">{l.type}</td>
-                    <td className="text-slate-300">{l.media_count}</td>
-                    <td className="text-slate-300">{fmtBytes(l.total_bytes)}</td>
+                    <td className="py-2 text-ink-600">{l.name}</td>
+                    <td className="text-ink-100">{l.type}</td>
+                    <td className="text-ink-100">{l.media_count}</td>
+                    <td className="text-ink-100">{fmtBytes(l.total_bytes)}</td>
                     <td>
                       <div className="flex items-center gap-2">
                         <div className="h-1 w-24 overflow-hidden rounded bg-white/10">
@@ -86,7 +86,7 @@ export function StoragePage() {
                             style={{ width: `${pct.toFixed(1)}%` }}
                           />
                         </div>
-                        <span className="text-xs text-slate-400">{pct.toFixed(1)}%</span>
+                        <span className="text-xs text-ink-50">{pct.toFixed(1)}%</span>
                       </div>
                     </td>
                   </tr>
@@ -98,7 +98,7 @@ export function StoragePage() {
       </section>
 
       <section className="space-y-3">
-        <h2 className="font-display text-xl font-semibold text-white">按容器格式</h2>
+        <h2 className="font-display text-xl font-semibold text-ink-600">按容器格式</h2>
         <div className="grid gap-3 sm:grid-cols-2 md:grid-cols-3">
           {data.by_container.map((c) => (
             <div
@@ -106,10 +106,10 @@ export function StoragePage() {
               className="glass-panel flex items-center justify-between !p-4"
             >
               <div>
-                <p className="text-xs uppercase tracking-wider text-slate-500">{c.container}</p>
-                <p className="font-display text-lg font-semibold text-white">{c.count} 项</p>
+                <p className="text-xs uppercase tracking-wider text-sand-500">{c.container}</p>
+                <p className="font-display text-lg font-semibold text-ink-600">{c.count} 项</p>
               </div>
-              <p className="text-sm text-slate-300">{fmtBytes(c.bytes)}</p>
+              <p className="text-sm text-ink-100">{fmtBytes(c.bytes)}</p>
             </div>
           ))}
         </div>
@@ -129,12 +129,12 @@ function Tile({
 }) {
   return (
     <div className="glass-panel flex items-center gap-3 !p-4">
-      <div className="rounded-lg border border-primary-400/40 bg-primary-400/10 p-2 text-primary-400">
+      <div className="rounded-lg border border-primary-400/40 bg-primary-400/10 p-2 text-brand-500">
         {icon}
       </div>
       <div>
-        <p className="text-xs uppercase tracking-wider text-slate-500">{label}</p>
-        <p className="font-display text-lg font-semibold text-white">{value}</p>
+        <p className="text-xs uppercase tracking-wider text-sand-500">{label}</p>
+        <p className="font-display text-lg font-semibold text-ink-600">{value}</p>
       </div>
     </div>
   )