TG Bot 命令交互 + UI 圆角色差深度优化 + 通知配置修复

## TG Bot 交互命令系统 (新增)
- telegram_bot.go: 命令路由 + /start /help /status /search /downloads /stats
- telegram_webhook.go: Webhook 接收 + Polling 管理端点
- Polling 模式: 无需公网 HTTPS, 服务器启动自动轮询
- HTML parse_mode 统一消息格式

## 通知配置 BUG 修复
- validateChannel 添加 email 类型支持
- 前后端字段统一: channel_type -> type
- ListByType 新增仓库方法

## UI 深度优化
- glass-panel: 添加 rounded-2xl + 可见边框 + padding
- card: 添加 p-4 sm:p-6
- 全局 rounded-md -> rounded-xl, 裸 rounded -> rounded-lg
- 500+ 深色硬编码类名清零
- text-gray-400 -> gray-500 色差提升
- 按钮组 flex-wrap 防溢出
- data-table 表格溢出截断

web/src/components/MediaCard.tsx

@@ -32,7 +32,7 @@ export const MediaCard = ({
               referrerPolicy="no-referrer"
             />
           ) : (
-            <div className="flex h-full w-full flex-col items-center justify-center gap-2 text-gray-400 bg-gray-50">
+            <div className="flex h-full w-full flex-col items-center justify-center gap-2 text-gray-500 bg-gray-50">
               <Film size={28} className="stroke-[1.5]" />
               <span className="text-[10px] uppercase tracking-wider font-bold">No Poster</span>
             </div>
@@ -40,7 +40,7 @@ export const MediaCard = ({
 
           {/* Episode count badge */}
           {count !== undefined && count > 1 && (
-            <span className="absolute right-3 top-3 inline-flex items-center gap-1 rounded-lg bg-[#111827]/90 px-2 py-1 text-[10px] font-bold text-white shadow-sm border border-white/10">
+            <span className="absolute right-3 top-3 inline-flex items-center gap-1 rounded-xl bg-[#111827]/90 px-2 py-1 text-[10px] font-bold text-white shadow-sm border border-gray-200">
               <Layers size={10} className="text-[#c9954a]" />
               <span>{count} 集</span>
             </span>
@@ -48,7 +48,7 @@ export const MediaCard = ({
 
           {/* Rating Badge */}
           {(rating || (media as any).rating) && (
-            <span className="absolute left-3 top-3 inline-flex items-center gap-0.5 rounded-lg bg-[#111827]/90 px-2 py-1 text-[10px] font-bold text-[#c9954a] shadow-sm border border-white/10">
+            <span className="absolute left-3 top-3 inline-flex items-center gap-0.5 rounded-xl bg-[#111827]/90 px-2 py-1 text-[10px] font-bold text-[#c9954a] shadow-sm border border-gray-200">
               <Star size={10} fill="currentColor" />
               <span>{(rating || (media as any).rating).toFixed(1)}</span>
             </span>
@@ -66,7 +66,7 @@ export const MediaCard = ({
                 <Play size={10} fill="currentColor" className="text-white" />
                 <span>立即观影</span>
               </span>
-              <p className="text-[10px] text-gray-300 font-semibold line-clamp-2 leading-relaxed">
+              <p className="text-[10px] text-gray-500 font-semibold line-clamp-2 leading-relaxed">
                 {media.overview || "暂无简介内容"}
               </p>
             </motion.div>
@@ -91,7 +91,7 @@ export const MediaCard = ({
           <div className="flex items-center justify-between text-[11px] text-gray-500 font-bold uppercase tracking-wider">
             <span>{media.year > 0 ? media.year : "未知年份"}</span>
             {media.video_codec && (
-              <span className="px-1.5 py-0.5 rounded-md bg-gray-50 text-gray-600 border border-gray-100">
+              <span className="px-1.5 py-0.5 rounded-xl bg-gray-50 text-gray-600 border border-gray-100">
                 {media.video_codec}
               </span>
             )}