Add master display UI with audio output management and styling

- Implement main.js for the master display functionality, including WebSocket connection, audio output management, and state handling.
- Create style.css for the master display's visual design, ensuring a cohesive look and feel with a dark theme and responsive layout.
- Integrate device management with a fallback for non-Electron environments, allowing users to select audio outputs.
- Add features for managing favorites, including toggling favorites and filtering by genre.
- Enhance user experience with a responsive favorites grid and drag-to-scroll functionality.

server/db/schema.sql

@@ -30,6 +30,8 @@ CREATE TABLE IF NOT EXISTS stations (
   genres      TEXT, -- JSON array
   description TEXT,
   image_url   TEXT,
+  image_path  TEXT,                          -- relative path under data/images, e.g. "stations/12.jpg"
+  image_source TEXT,                         -- 'remote' | 'scraped' | 'upload'
   source      TEXT NOT NULL CHECK (source IN ('seed','radiobrowser','manual')),
   source_ref  TEXT,
   category    TEXT,
@@ -93,8 +95,43 @@ CREATE INDEX IF NOT EXISTS idx_votes_station ON station_votes(station_id);
 
 -- Aggregate play counter. Cheaper than COUNT(*) over play_history every render
 -- and lets anonymous/public listing show play counts without exposing history.
+-- `total_play_ms` and `sessions` accumulate from closed play_history rows so
+-- the leaderboard can rank by actual listen time, not just play-button taps.
 CREATE TABLE IF NOT EXISTS station_plays (
   station_id     INTEGER PRIMARY KEY REFERENCES stations(id) ON DELETE CASCADE,
   plays          INTEGER NOT NULL DEFAULT 0,
+  sessions       INTEGER NOT NULL DEFAULT 0,
+  total_play_ms  INTEGER NOT NULL DEFAULT 0,
   last_played_at TEXT
 );
+
+-- Named listening rooms. One "display" client + many controller/panel clients
+-- per room share state (now-playing, volume, votes). A personal room is
+-- auto-provisioned per user so single-user kiosks Just Work.
+CREATE TABLE IF NOT EXISTS rooms (
+  id         INTEGER PRIMARY KEY AUTOINCREMENT,
+  slug       TEXT NOT NULL UNIQUE,
+  name       TEXT NOT NULL,
+  created_by INTEGER REFERENCES users(id) ON DELETE SET NULL,
+  created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS room_members (
+  room_id INTEGER NOT NULL REFERENCES rooms(id) ON DELETE CASCADE,
+  user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  role    TEXT NOT NULL DEFAULT 'member' CHECK (role IN ('owner','member','guest')),
+  created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (room_id, user_id)
+);
+CREATE INDEX IF NOT EXISTS idx_room_members_user ON room_members(user_id);
+
+-- Last-known playback state per room. Persisted so clients reconnecting see
+-- the same now-playing card immediately, even after a server restart.
+CREATE TABLE IF NOT EXISTS room_state (
+  room_id    INTEGER PRIMARY KEY REFERENCES rooms(id) ON DELETE CASCADE,
+  station_id INTEGER REFERENCES stations(id) ON DELETE SET NULL,
+  playing    INTEGER NOT NULL DEFAULT 0,
+  volume     REAL NOT NULL DEFAULT 0.7,
+  updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+