Overhaul RSS feed widget: persistence, multi-feed management, search, bookmarks

- Add rss_feeds + rss_items tables with indexes and HN default seed
- Add 5-min background RSS sync loop in monitor.js with 90-day prune
- New /api/rss/feeds route for feed CRUD with immediate fetch on add
- Rewrite /api/rss route with search, feed filter, pagination, read/bookmark PATCH
- Full NewsFeed component rewrite: feed manager, search bar, filter pills,
  read/unread tracking, bookmarks, favicons, auto-refresh with new items badge
- Remove placeholder widget, NewsFeed now spans 4 cols / 3 rows
- Add rss-parser deps to Dockerfile for standalone monitor

lib/db.ts

@@ -45,7 +45,40 @@ export async function getDb() {
 
     CREATE INDEX IF NOT EXISTS idx_uptime_logs_service_timestamp
       ON uptime_logs(service_name, timestamp);
+
+    CREATE TABLE IF NOT EXISTS rss_feeds (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      name TEXT NOT NULL,
+      url TEXT NOT NULL UNIQUE,
+      last_fetched DATETIME,
+      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+    );
+
+    CREATE TABLE IF NOT EXISTS rss_items (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      feed_id INTEGER NOT NULL,
+      title TEXT NOT NULL,
+      link TEXT NOT NULL UNIQUE,
+      pub_date DATETIME,
+      creator TEXT,
+      snippet TEXT,
+      read INTEGER DEFAULT 0,
+      bookmarked INTEGER DEFAULT 0,
+      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+    );
+
+    CREATE INDEX IF NOT EXISTS idx_rss_items_feed ON rss_items(feed_id);
+    CREATE INDEX IF NOT EXISTS idx_rss_items_pubdate ON rss_items(pub_date DESC);
   `);
 
+  // Seed default HN feed if rss_feeds is empty
+  const feedCount = await db.get('SELECT COUNT(*) as cnt FROM rss_feeds');
+  if (feedCount?.cnt === 0) {
+    await db.run(
+      'INSERT INTO rss_feeds (name, url) VALUES (?, ?)',
+      'Hacker News', 'https://news.ycombinator.com/rss'
+    );
+  }
+
   return db;
 }