feat: 記事ごとのポッドキャスト生成と新規記事検出システム、モダンUIの実装

- 新規記事検出システム: 記事の重複チェックと新規記事のみ処理
- 記事単位ポッドキャスト: フィード統合から記事個別エピソードに変更
- 6時間間隔バッチ処理: 自動定期実行スケジュールの改善
- 完全UIリニューアル: ダッシュボード・フィード管理・エピソード管理の3画面構成
- アクセシビリティ強化: ARIA属性、キーボードナビ、高コントラスト対応
- データベース刷新: feeds/articles/episodes階層構造への移行
- 中央集権設定管理: services/config.ts による設定統一
- エラーハンドリング改善: 全モジュールでの堅牢なエラー処理
- TypeScript型安全性向上: null安全性とインターフェース改善

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/components/Dashboard.tsx

@@ -0,0 +1,255 @@
+import { useEffect, useState } from "react";
+
+interface Stats {
+  totalFeeds: number;
+  activeFeeds: number;
+  totalEpisodes: number;
+  lastUpdated: string;
+}
+
+interface RecentEpisode {
+  id: string;
+  title: string;
+  createdAt: string;
+  article: {
+    title: string;
+    link: string;
+  };
+  feed: {
+    title: string;
+  };
+}
+
+export default function Dashboard() {
+  const [stats, setStats] = useState<Stats | null>(null);
+  const [recentEpisodes, setRecentEpisodes] = useState<RecentEpisode[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    fetchDashboardData();
+  }, []);
+
+  const fetchDashboardData = async () => {
+    try {
+      // Fetch stats and recent episodes in parallel
+      const [statsResponse, episodesResponse] = await Promise.all([
+        fetch("/api/stats"),
+        fetch("/api/episodes")
+      ]);
+
+      if (!statsResponse.ok || !episodesResponse.ok) {
+        throw new Error("Failed to fetch dashboard data");
+      }
+
+      const statsData = await statsResponse.json();
+      const episodesData = await episodesResponse.json();
+
+      setStats(statsData);
+      setRecentEpisodes(episodesData.slice(0, 5)); // Show latest 5 episodes
+      setLoading(false);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "エラーが発生しました");
+      setLoading(false);
+    }
+  };
+
+  const triggerBatchProcess = async () => {
+    try {
+      const response = await fetch("/api/batch/trigger", { method: "POST" });
+      if (response.ok) {
+        alert("バッチ処理を開始しました。新しいエピソードの生成には時間がかかる場合があります。");
+      } else {
+        alert("バッチ処理の開始に失敗しました。");
+      }
+    } catch (error) {
+      alert("エラーが発生しました。");
+    }
+  };
+
+  if (loading) {
+    return (
+      <div className="flex items-center justify-center py-12">
+        <div className="flex items-center space-x-3">
+          <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-blue-500"></div>
+          <span className="text-gray-600">読み込み中...</span>
+        </div>
+      </div>
+    );
+  }
+
+  if (error) {
+    return (
+      <div className="bg-red-50 border border-red-200 rounded-lg p-4">
+        <div className="flex items-center">
+          <div className="text-red-400">
+            <svg className="w-5 h-5" fill="currentColor" viewBox="0 0 20 20">
+              <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clipRule="evenodd" />
+            </svg>
+          </div>
+          <div className="ml-3">
+            <h3 className="text-sm font-medium text-red-800">エラー</h3>
+            <p className="text-sm text-red-700">{error}</p>
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  return (
+    <div className="space-y-8">
+      {/* Stats Cards */}
+      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-6">
+        <div className="bg-white rounded-xl shadow-sm p-6 border border-gray-100">
+          <div className="flex items-center">
+            <div className="flex-shrink-0">
+              <div className="w-8 h-8 bg-blue-100 rounded-lg flex items-center justify-center">
+                <span role="img" aria-hidden="true" className="text-lg">📡</span>
+              </div>
+            </div>
+            <div className="ml-4">
+              <p className="text-sm font-medium text-gray-600">総フィード数</p>
+              <p className="text-2xl font-semibold text-gray-900">{stats?.totalFeeds || 0}</p>
+            </div>
+          </div>
+        </div>
+
+        <div className="bg-white rounded-xl shadow-sm p-6 border border-gray-100">
+          <div className="flex items-center">
+            <div className="flex-shrink-0">
+              <div className="w-8 h-8 bg-green-100 rounded-lg flex items-center justify-center">
+                <span role="img" aria-hidden="true" className="text-lg">✅</span>
+              </div>
+            </div>
+            <div className="ml-4">
+              <p className="text-sm font-medium text-gray-600">アクティブフィード</p>
+              <p className="text-2xl font-semibold text-gray-900">{stats?.activeFeeds || 0}</p>
+            </div>
+          </div>
+        </div>
+
+        <div className="bg-white rounded-xl shadow-sm p-6 border border-gray-100">
+          <div className="flex items-center">
+            <div className="flex-shrink-0">
+              <div className="w-8 h-8 bg-purple-100 rounded-lg flex items-center justify-center">
+                <span role="img" aria-hidden="true" className="text-lg">🎧</span>
+              </div>
+            </div>
+            <div className="ml-4">
+              <p className="text-sm font-medium text-gray-600">総エピソード数</p>
+              <p className="text-2xl font-semibold text-gray-900">{stats?.totalEpisodes || 0}</p>
+            </div>
+          </div>
+        </div>
+
+        <div className="bg-white rounded-xl shadow-sm p-6 border border-gray-100">
+          <div className="flex items-center">
+            <div className="flex-shrink-0">
+              <div className="w-8 h-8 bg-yellow-100 rounded-lg flex items-center justify-center">
+                <span role="img" aria-hidden="true" className="text-lg">🕒</span>
+              </div>
+            </div>
+            <div className="ml-4">
+              <p className="text-sm font-medium text-gray-600">最終更新</p>
+              <p className="text-sm font-semibold text-gray-900">
+                {stats?.lastUpdated ? new Date(stats.lastUpdated).toLocaleDateString('ja-JP') : '未取得'}
+              </p>
+            </div>
+          </div>
+        </div>
+      </div>
+
+      {/* Action Cards */}
+      <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
+        <div className="bg-gradient-to-r from-blue-500 to-purple-600 rounded-xl shadow-sm p-6 text-white">
+          <div className="flex items-center justify-between">
+            <div>
+              <h3 className="text-lg font-semibold">手動バッチ実行</h3>
+              <p className="text-blue-100 text-sm mt-1">
+                新しい記事をすぐにチェックしてポッドキャストを生成
+              </p>
+            </div>
+            <button
+              onClick={triggerBatchProcess}
+              className="bg-white bg-opacity-20 hover:bg-opacity-30 text-white font-medium py-2 px-4 rounded-lg transition-colors duration-200 focus:outline-none focus:ring-2 focus:ring-white focus:ring-opacity-50"
+              aria-label="バッチ処理を手動実行"
+            >
+              実行
+            </button>
+          </div>
+        </div>
+
+        <div className="bg-white rounded-xl shadow-sm p-6 border border-gray-100">
+          <div className="flex items-center justify-between">
+            <div>
+              <h3 className="text-lg font-semibold text-gray-900">システム状態</h3>
+              <div className="flex items-center space-x-2 mt-2">
+                <div className="w-3 h-3 bg-green-400 rounded-full animate-pulse"></div>
+                <span className="text-sm text-gray-600">自動バッチ処理 (6時間間隔)</span>
+              </div>
+            </div>
+            <div className="text-green-500">
+              <svg className="w-8 h-8" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 12l2 2 4-4m6 2a9 9 0 11-18 0 9 9 0 0118 0z" />
+              </svg>
+            </div>
+          </div>
+        </div>
+      </div>
+
+      {/* Recent Episodes */}
+      <div className="bg-white rounded-xl shadow-sm p-6 border border-gray-100">
+        <div className="flex items-center justify-between mb-6">
+          <h3 className="text-lg font-semibold text-gray-900">最新エピソード</h3>
+          <span className="text-sm text-gray-500">{recentEpisodes.length} エピソード</span>
+        </div>
+        
+        {recentEpisodes.length === 0 ? (
+          <div className="text-center py-8">
+            <div className="w-16 h-16 bg-gray-100 rounded-full flex items-center justify-center mx-auto mb-4">
+              <span role="img" aria-hidden="true" className="text-2xl">🎧</span>
+            </div>
+            <p className="text-gray-500">まだエピソードがありません</p>
+            <p className="text-sm text-gray-400 mt-1">フィードを追加してバッチ処理を実行してください</p>
+          </div>
+        ) : (
+          <div className="space-y-4">
+            {recentEpisodes.map((episode) => (
+              <div
+                key={episode.id}
+                className="flex items-start space-x-4 p-4 rounded-lg border border-gray-100 hover:bg-gray-50 transition-colors duration-200"
+              >
+                <div className="w-10 h-10 bg-gradient-to-r from-blue-400 to-purple-500 rounded-lg flex items-center justify-center text-white font-semibold text-sm">
+                  <span role="img" aria-hidden="true">🎵</span>
+                </div>
+                <div className="flex-1 min-w-0">
+                  <h4 className="text-sm font-medium text-gray-900 truncate">
+                    {episode.title}
+                  </h4>
+                  <p className="text-sm text-gray-500 mt-1">
+                    {episode.feed?.title} • {new Date(episode.createdAt).toLocaleDateString('ja-JP')}
+                  </p>
+                  {episode.article && (
+                    <a
+                      href={episode.article.link}
+                      target="_blank"
+                      rel="noopener noreferrer"
+                      className="text-xs text-blue-600 hover:text-blue-800 mt-1 inline-block"
+                    >
+                      元記事を見る →
+                    </a>
+                  )}
+                </div>
+                <div className="flex-shrink-0">
+                  <span className="inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium bg-green-100 text-green-800">
+                    生成済み
+                  </span>
+                </div>
+              </div>
+            ))}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

frontend/src/components/EpisodePlayer.tsx

@@ -1,24 +1,62 @@
-import { useEffect, useState } from "react";
+import { useEffect, useState, useRef } from "react";
 
 interface Episode {
   id: string;
   title: string;
-  pubDate: string;
+  description?: string;
   audioPath: string;
-  sourceLink: string;
+  duration?: number;
+  fileSize?: number;
+  createdAt: string;
+  article: {
+    id: string;
+    title: string;
+    link: string;
+    description?: string;
+    pubDate: string;
+  };
+  feed: {
+    id: string;
+    title?: string;
+    url: string;
+  };
 }
 
 export default function EpisodePlayer() {
   const [episodes, setEpisodes] = useState<Episode[]>([]);
   const [selectedEpisode, setSelectedEpisode] = useState<Episode | null>(null);
-  const [audioUrl, setAudioUrl] = useState<string | null>(null);
+  const [isPlaying, setIsPlaying] = useState(false);
+  const [currentTime, setCurrentTime] = useState(0);
+  const [duration, setDuration] = useState(0);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
+  const [searchTerm, setSearchTerm] = useState("");
+  
+  const audioRef = useRef<HTMLAudioElement>(null);
 
   useEffect(() => {
     fetchEpisodes();
   }, []);
 
+  useEffect(() => {
+    const audio = audioRef.current;
+    if (!audio) return;
+
+    const updateTime = () => setCurrentTime(audio.currentTime);
+    const updateDuration = () => setDuration(audio.duration);
+    const handleEnded = () => setIsPlaying(false);
+
+    audio.addEventListener('timeupdate', updateTime);
+    audio.addEventListener('loadedmetadata', updateDuration);
+    audio.addEventListener('ended', handleEnded);
+
+    return () => {
+      audio.removeEventListener('timeupdate', updateTime);
+      audio.removeEventListener('loadedmetadata', updateDuration);
+      audio.removeEventListener('ended', handleEnded);
+    };
+  }, [selectedEpisode]);
+
   const fetchEpisodes = async () => {
     try {
       const response = await fetch("/api/episodes");
@@ -35,45 +73,267 @@ export default function EpisodePlayer() {
   };
 
   const handlePlay = (episode: Episode) => {
-    setSelectedEpisode(episode);
-    setAudioUrl(`/podcast_audio/${episode.audioPath}`);
+    if (selectedEpisode?.id === episode.id) {
+      // Toggle play/pause for the same episode
+      if (isPlaying) {
+        audioRef.current?.pause();
+        setIsPlaying(false);
+      } else {
+        audioRef.current?.play();
+        setIsPlaying(true);
+      }
+    } else {
+      // Play new episode
+      setSelectedEpisode(episode);
+      setIsPlaying(true);
+      setCurrentTime(0);
+    }
   };
 
-  if (loading) return <div>読み込み中...</div>;
-  if (error) return <div className="text-red-500">エラー: {error}</div>;
+  const handleSeek = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const audio = audioRef.current;
+    if (audio) {
+      const newTime = parseFloat(e.target.value);
+      audio.currentTime = newTime;
+      setCurrentTime(newTime);
+    }
+  };
+
+  const formatTime = (time: number) => {
+    if (isNaN(time)) return "0:00";
+    const minutes = Math.floor(time / 60);
+    const seconds = Math.floor(time % 60);
+    return `${minutes}:${seconds.toString().padStart(2, '0')}`;
+  };
+
+  const formatFileSize = (bytes?: number) => {
+    if (!bytes) return "不明";
+    const mb = bytes / (1024 * 1024);
+    return `${mb.toFixed(1)} MB`;
+  };
+
+  const filteredEpisodes = episodes.filter(episode =>
+    episode.title.toLowerCase().includes(searchTerm.toLowerCase()) ||
+    episode.article.title.toLowerCase().includes(searchTerm.toLowerCase()) ||
+    episode.feed.title?.toLowerCase().includes(searchTerm.toLowerCase())
+  );
+
+  if (loading) {
+    return (
+      <div className="flex items-center justify-center py-12">
+        <div className="flex items-center space-x-3">
+          <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-purple-500"></div>
+          <span className="text-gray-600">読み込み中...</span>
+        </div>
+      </div>
+    );
+  }
+
+  if (error) {
+    return (
+      <div className="bg-red-50 border border-red-200 rounded-lg p-4">
+        <div className="flex items-center">
+          <div className="text-red-400">
+            <svg className="w-5 h-5" fill="currentColor" viewBox="0 0 20 20">
+              <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clipRule="evenodd" />
+            </svg>
+          </div>
+          <div className="ml-3">
+            <h3 className="text-sm font-medium text-red-800">エラー</h3>
+            <p className="text-sm text-red-700">{error}</p>
+          </div>
+        </div>
+      </div>
+    );
+  }
 
   return (
-    <div className="space-y-4">
-      <h3 className="text-lg font-medium">最近のエピソード</h3>
-      <div className="space-y-2">
-        {episodes.map((episode) => (
-          <div
-            key={episode.id}
-            className="flex justify-between items-center p-2 hover:bg-gray-50 rounded"
-          >
-            <span>{episode.title}</span>
-            <button
-              onClick={() => handlePlay(episode)}
-              className="px-3 py-1 bg-blue-500 text-white rounded hover:bg-blue-600"
-            >
-              再生
-            </button>
-          </div>
-        ))}
+    <div className="space-y-6">
+      {/* Search */}
+      <div className="relative">
+        <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
+          <svg className="h-5 w-5 text-gray-400" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z" />
+          </svg>
+        </div>
+        <input
+          type="text"
+          placeholder="エピソードを検索..."
+          value={searchTerm}
+          onChange={(e) => setSearchTerm(e.target.value)}
+          className="block w-full pl-10 pr-3 py-2 border border-gray-300 rounded-lg focus:ring-2 focus:ring-purple-500 focus:border-transparent"
+        />
       </div>
 
+      {/* Audio Player */}
       {selectedEpisode && (
-        <div className="mt-6">
-          <h4 className="text-md font-semibold mb-2">
-            再生中: {selectedEpisode.title}
-          </h4>
-          {audioUrl ? (
-            <audio src={audioUrl} controls className="w-full" />
-          ) : (
-            <div>音声ファイルを読み込み中...</div>
-          )}
+        <div className="bg-gradient-to-r from-purple-50 to-blue-50 rounded-xl p-6 border border-purple-100">
+          <div className="flex items-center space-x-4 mb-4">
+            <div className="w-12 h-12 bg-gradient-to-r from-purple-500 to-blue-600 rounded-full flex items-center justify-center text-white">
+              <span role="img" aria-hidden="true" className="text-xl">🎵</span>
+            </div>
+            <div className="flex-1 min-w-0">
+              <h3 className="text-lg font-semibold text-gray-900 truncate">{selectedEpisode.title}</h3>
+              <p className="text-sm text-gray-600">{selectedEpisode.feed.title}</p>
+            </div>
+            <button
+              onClick={() => handlePlay(selectedEpisode)}
+              className="w-12 h-12 bg-white rounded-full shadow-md flex items-center justify-center hover:shadow-lg transition-shadow duration-200"
+              aria-label={isPlaying ? "一時停止" : "再生"}
+            >
+              {isPlaying ? (
+                <svg className="w-6 h-6 text-gray-700" fill="currentColor" viewBox="0 0 20 20">
+                  <path fillRule="evenodd" d="M18 10a8 8 0 11-16 0 8 8 0 0116 0zM7 8a1 1 0 012 0v4a1 1 0 11-2 0V8zm5-1a1 1 0 00-1 1v4a1 1 0 102 0V8a1 1 0 00-1-1z" clipRule="evenodd" />
+                </svg>
+              ) : (
+                <svg className="w-6 h-6 text-gray-700 ml-1" fill="currentColor" viewBox="0 0 20 20">
+                  <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM9.555 7.168A1 1 0 008 8v4a1 1 0 001.555.832l3-2a1 1 0 000-1.664l-3-2z" clipRule="evenodd" />
+                </svg>
+              )}
+            </button>
+          </div>
+          
+          {/* Progress Bar */}
+          <div className="space-y-2">
+            <input
+              type="range"
+              min="0"
+              max={duration || 0}
+              value={currentTime}
+              onChange={handleSeek}
+              className="w-full h-2 bg-gray-200 rounded-lg appearance-none cursor-pointer slider"
+              aria-label="再生位置"
+            />
+            <div className="flex justify-between text-xs text-gray-500">
+              <span>{formatTime(currentTime)}</span>
+              <span>{formatTime(duration)}</span>
+            </div>
+          </div>
+
+          {/* Episode Info */}
+          <div className="mt-4 space-y-2 text-sm">
+            {selectedEpisode.description && (
+              <p className="text-gray-700">{selectedEpisode.description}</p>
+            )}
+            <div className="flex items-center space-x-4 text-gray-500">
+              <span>🗓️ {new Date(selectedEpisode.createdAt).toLocaleDateString('ja-JP')}</span>
+              <span>💾 {formatFileSize(selectedEpisode.fileSize)}</span>
+              {selectedEpisode.article.link && (
+                <a
+                  href={selectedEpisode.article.link}
+                  target="_blank"
+                  rel="noopener noreferrer"
+                  className="text-blue-600 hover:text-blue-800"
+                >
+                  📄 元記事
+                </a>
+              )}
+            </div>
+          </div>
+
+          <audio
+            ref={audioRef}
+            src={`/podcast_audio/${selectedEpisode.audioPath}`}
+            onPlay={() => setIsPlaying(true)}
+            onPause={() => setIsPlaying(false)}
+            className="hidden"
+          />
         </div>
       )}
+
+      {/* Episodes List */}
+      <div>
+        <div className="flex items-center justify-between mb-4">
+          <h3 className="text-lg font-semibold text-gray-900">エピソード一覧</h3>
+          <span className="text-sm text-gray-500">{filteredEpisodes.length} エピソード</span>
+        </div>
+
+        {filteredEpisodes.length === 0 ? (
+          <div className="text-center py-12 bg-gray-50 rounded-xl">
+            <div className="w-16 h-16 bg-gray-200 rounded-full flex items-center justify-center mx-auto mb-4">
+              <span role="img" aria-hidden="true" className="text-2xl">🎧</span>
+            </div>
+            <h3 className="text-lg font-medium text-gray-900 mb-2">
+              {searchTerm ? "検索結果がありません" : "エピソードがありません"}
+            </h3>
+            <p className="text-gray-500">
+              {searchTerm ? "別のキーワードで検索してみてください" : "フィードを追加してバッチ処理を実行してください"}
+            </p>
+          </div>
+        ) : (
+          <div className="grid gap-4">
+            {filteredEpisodes.map((episode) => (
+              <div
+                key={episode.id}
+                className={`border rounded-xl p-4 transition-all duration-200 cursor-pointer ${
+                  selectedEpisode?.id === episode.id
+                    ? 'border-purple-300 bg-purple-50 shadow-md'
+                    : 'border-gray-200 bg-white hover:border-gray-300 hover:shadow-sm'
+                }`}
+                onClick={() => handlePlay(episode)}
+                role="button"
+                tabIndex={0}
+                onKeyDown={(e) => {
+                  if (e.key === 'Enter' || e.key === ' ') {
+                    e.preventDefault();
+                    handlePlay(episode);
+                  }
+                }}
+                aria-label={`エピソード: ${episode.title}`}
+              >
+                <div className="flex items-start space-x-4">
+                  <div className="flex-shrink-0">
+                    <div className={`w-12 h-12 rounded-full flex items-center justify-center ${
+                      selectedEpisode?.id === episode.id
+                        ? 'bg-purple-500 text-white'
+                        : 'bg-gray-100 text-gray-600'
+                    }`}>
+                      {selectedEpisode?.id === episode.id && isPlaying ? (
+                        <svg className="w-6 h-6" fill="currentColor" viewBox="0 0 20 20">
+                          <path fillRule="evenodd" d="M18 10a8 8 0 11-16 0 8 8 0 0116 0zM7 8a1 1 0 012 0v4a1 1 0 11-2 0V8zm5-1a1 1 0 00-1 1v4a1 1 0 102 0V8a1 1 0 00-1-1z" clipRule="evenodd" />
+                        </svg>
+                      ) : (
+                        <svg className="w-6 h-6" fill="currentColor" viewBox="0 0 20 20">
+                          <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM9.555 7.168A1 1 0 008 8v4a1 1 0 001.555.832l3-2a1 1 0 000-1.664l-3-2z" clipRule="evenodd" />
+                        </svg>
+                      )}
+                    </div>
+                  </div>
+                  
+                  <div className="flex-1 min-w-0">
+                    <h4 className="text-base font-medium text-gray-900 mb-1 line-clamp-2">
+                      {episode.title}
+                    </h4>
+                    <p className="text-sm text-gray-600 mb-2 line-clamp-1">
+                      {episode.feed.title}
+                    </p>
+                    {episode.description && (
+                      <p className="text-sm text-gray-500 mb-2 line-clamp-2">
+                        {episode.description}
+                      </p>
+                    )}
+                    <div className="flex items-center space-x-4 text-xs text-gray-500">
+                      <span>📅 {new Date(episode.createdAt).toLocaleDateString('ja-JP')}</span>
+                      <span>💾 {formatFileSize(episode.fileSize)}</span>
+                      {episode.article.link && (
+                        <a
+                          href={episode.article.link}
+                          target="_blank"
+                          rel="noopener noreferrer"
+                          className="text-blue-600 hover:text-blue-800"
+                          onClick={(e) => e.stopPropagation()}
+                        >
+                          📄 元記事
+                        </a>
+                      )}
+                    </div>
+                  </div>
+                </div>
+              </div>
+            ))}
+          </div>
+        )}
+      </div>
     </div>
   );
-}
+}

frontend/src/components/FeedManager.tsx

@@ -0,0 +1,243 @@
+import { useEffect, useState } from "react";
+
+interface Feed {
+  id: string;
+  url: string;
+  title?: string;
+  description?: string;
+  lastUpdated?: string;
+  createdAt: string;
+  active: boolean;
+}
+
+export default function FeedManager() {
+  const [feeds, setFeeds] = useState<Feed[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const [newFeedUrl, setNewFeedUrl] = useState("");
+  const [addingFeed, setAddingFeed] = useState(false);
+
+  useEffect(() => {
+    fetchFeeds();
+  }, []);
+
+  const fetchFeeds = async () => {
+    try {
+      setLoading(true);
+      const response = await fetch("/api/feeds");
+      if (!response.ok) {
+        throw new Error("フィードの取得に失敗しました");
+      }
+      const data = await response.json();
+      setFeeds(data);
+      setError(null);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "エラーが発生しました");
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  const addFeed = async (e: React.FormEvent) => {
+    e.preventDefault();
+    
+    if (!newFeedUrl.trim()) {
+      alert("フィードURLを入力してください");
+      return;
+    }
+
+    if (!newFeedUrl.startsWith('http')) {
+      alert("有効なURLを入力してください");
+      return;
+    }
+
+    try {
+      setAddingFeed(true);
+      const response = await fetch("/api/feeds", {
+        method: "POST",
+        headers: {
+          "Content-Type": "application/json",
+        },
+        body: JSON.stringify({ feedUrl: newFeedUrl }),
+      });
+
+      const result = await response.json();
+
+      if (response.ok) {
+        if (result.result === "EXISTS") {
+          alert("このフィードは既に登録されています");
+        } else {
+          alert("フィードが正常に追加されました");
+          setNewFeedUrl("");
+          fetchFeeds(); // Refresh the list
+        }
+      } else {
+        alert(result.error || "フィードの追加に失敗しました");
+      }
+    } catch (err) {
+      alert("エラーが発生しました");
+    } finally {
+      setAddingFeed(false);
+    }
+  };
+
+  if (loading) {
+    return (
+      <div className="flex items-center justify-center py-12">
+        <div className="flex items-center space-x-3">
+          <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-blue-500"></div>
+          <span className="text-gray-600">読み込み中...</span>
+        </div>
+      </div>
+    );
+  }
+
+  return (
+    <div className="space-y-6">
+      {/* Add New Feed Form */}
+      <div className="bg-gradient-to-r from-blue-50 to-purple-50 rounded-xl p-6 border border-blue-100">
+        <h3 className="text-lg font-semibold text-gray-900 mb-4">新しいフィードを追加</h3>
+        <form onSubmit={addFeed} className="space-y-4">
+          <div>
+            <label htmlFor="feedUrl" className="block text-sm font-medium text-gray-700 mb-2">
+              RSS フィード URL
+            </label>
+            <div className="flex space-x-3">
+              <input
+                type="url"
+                id="feedUrl"
+                value={newFeedUrl}
+                onChange={(e) => setNewFeedUrl(e.target.value)}
+                placeholder="https://example.com/feed.xml"
+                className="flex-1 border border-gray-300 rounded-lg px-4 py-2 focus:ring-2 focus:ring-blue-500 focus:border-transparent"
+                disabled={addingFeed}
+                aria-describedby="feedUrl-help"
+              />
+              <button
+                type="submit"
+                disabled={addingFeed || !newFeedUrl.trim()}
+                className="px-6 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed transition-colors duration-200"
+              >
+                {addingFeed ? (
+                  <div className="flex items-center space-x-2">
+                    <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-white"></div>
+                    <span>追加中...</span>
+                  </div>
+                ) : (
+                  "追加"
+                )}
+              </button>
+            </div>
+            <p id="feedUrl-help" className="text-xs text-gray-500 mt-2">
+              RSS または Atom フィードの URL を入力してください
+            </p>
+          </div>
+        </form>
+      </div>
+
+      {/* Error Display */}
+      {error && (
+        <div className="bg-red-50 border border-red-200 rounded-lg p-4">
+          <div className="flex items-center">
+            <div className="text-red-400">
+              <svg className="w-5 h-5" fill="currentColor" viewBox="0 0 20 20">
+                <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clipRule="evenodd" />
+              </svg>
+            </div>
+            <div className="ml-3">
+              <h3 className="text-sm font-medium text-red-800">エラー</h3>
+              <p className="text-sm text-red-700">{error}</p>
+            </div>
+          </div>
+        </div>
+      )}
+
+      {/* Feeds List */}
+      <div>
+        <div className="flex items-center justify-between mb-4">
+          <h3 className="text-lg font-semibold text-gray-900">登録済みフィード</h3>
+          <span className="text-sm text-gray-500">{feeds.length} フィード</span>
+        </div>
+
+        {feeds.length === 0 ? (
+          <div className="text-center py-12 bg-gray-50 rounded-xl">
+            <div className="w-16 h-16 bg-gray-200 rounded-full flex items-center justify-center mx-auto mb-4">
+              <span role="img" aria-hidden="true" className="text-2xl">📡</span>
+            </div>
+            <h3 className="text-lg font-medium text-gray-900 mb-2">フィードがありません</h3>
+            <p className="text-gray-500">上のフォームから RSS フィードを追加してください</p>
+          </div>
+        ) : (
+          <div className="grid gap-4">
+            {feeds.map((feed) => (
+              <div
+                key={feed.id}
+                className="bg-white border border-gray-200 rounded-xl p-6 hover:shadow-md transition-shadow duration-200"
+              >
+                <div className="flex items-start justify-between">
+                  <div className="flex-1 min-w-0">
+                    <div className="flex items-center space-x-3 mb-2">
+                      <div className={`w-3 h-3 rounded-full ${feed.active ? 'bg-green-400' : 'bg-gray-400'}`}></div>
+                      <h4 className="text-lg font-medium text-gray-900 truncate">
+                        {feed.title || 'タイトル未取得'}
+                      </h4>
+                    </div>
+                    
+                    {feed.description && (
+                      <p className="text-sm text-gray-600 mb-3 line-clamp-2">
+                        {feed.description}
+                      </p>
+                    )}
+                    
+                    <div className="space-y-2">
+                      <div className="flex items-center space-x-2">
+                        <span className="text-xs font-medium text-gray-500">URL:</span>
+                        <a
+                          href={feed.url}
+                          target="_blank"
+                          rel="noopener noreferrer"
+                          className="text-xs text-blue-600 hover:text-blue-800 truncate max-w-xs"
+                          title={feed.url}
+                        >
+                          {feed.url}
+                        </a>
+                      </div>
+                      
+                      <div className="flex items-center space-x-4 text-xs text-gray-500">
+                        <span>追加日: {new Date(feed.createdAt).toLocaleDateString('ja-JP')}</span>
+                        {feed.lastUpdated && (
+                          <span>最終更新: {new Date(feed.lastUpdated).toLocaleDateString('ja-JP')}</span>
+                        )}
+                      </div>
+                    </div>
+                  </div>
+                  
+                  <div className="flex items-center space-x-2 ml-4">
+                    <span className={`inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium ${
+                      feed.active 
+                        ? 'bg-green-100 text-green-800' 
+                        : 'bg-gray-100 text-gray-800'
+                    }`}>
+                      {feed.active ? 'アクティブ' : '無効'}
+                    </span>
+                    
+                    {/* Future: Add edit/delete buttons here */}
+                    <button
+                      className="text-gray-400 hover:text-gray-600 p-1"
+                      title="設定"
+                      aria-label={`${feed.title || feed.url}の設定`}
+                    >
+                      <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 5v.01M12 12v.01M12 19v.01M12 6a1 1 0 110-2 1 1 0 010 2zm0 7a1 1 0 110-2 1 1 0 010 2zm0 7a1 1 0 110-2 1 1 0 010 2z" />
+                      </svg>
+                    </button>
+                  </div>
+                </div>
+              </div>
+            ))}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}