Add player functionality with HLS support and API integration

- Implemented a new Player class in player.js to handle audio playback, including HLS support using hls.js.
- Created a shared API module in api.js for making HTTP requests with proper error handling.
- Added DOM utility functions in dom.js for creating and clearing elements.
- Introduced WebSocket connection handling in ws.js for real-time updates.
- Developed a comprehensive CSS stylesheet for styling the application, including a high-contrast theme.

server/db/schema.sql

@@ -0,0 +1,80 @@
+CREATE TABLE IF NOT EXISTS users (
+  id            INTEGER PRIMARY KEY AUTOINCREMENT,
+  username      TEXT NOT NULL UNIQUE,
+  password_hash TEXT NOT NULL,
+  role          TEXT NOT NULL DEFAULT 'user' CHECK (role IN ('admin','user')),
+  created_at    TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS sessions (
+  token      TEXT PRIMARY KEY,
+  user_id    INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  expires_at TEXT NOT NULL,
+  created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE TABLE IF NOT EXISTS profiles (
+  user_id        INTEGER PRIMARY KEY REFERENCES users(id) ON DELETE CASCADE,
+  display_name   TEXT,
+  theme          TEXT DEFAULT 'dark',
+  default_volume REAL DEFAULT 0.7
+);
+
+CREATE TABLE IF NOT EXISTS stations (
+  id          INTEGER PRIMARY KEY AUTOINCREMENT,
+  uuid        TEXT UNIQUE,
+  name        TEXT NOT NULL,
+  slug        TEXT NOT NULL UNIQUE,
+  homepage    TEXT,
+  country     TEXT,
+  genres      TEXT, -- JSON array
+  description TEXT,
+  image_url   TEXT,
+  source      TEXT NOT NULL CHECK (source IN ('seed','radiobrowser','manual')),
+  source_ref  TEXT,
+  category    TEXT,
+  created_by  INTEGER REFERENCES users(id) ON DELETE SET NULL,
+  enabled     INTEGER NOT NULL DEFAULT 1,
+  created_at  TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  updated_at  TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX IF NOT EXISTS idx_stations_enabled  ON stations(enabled);
+CREATE INDEX IF NOT EXISTS idx_stations_source   ON stations(source);
+CREATE INDEX IF NOT EXISTS idx_stations_category ON stations(category);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_stations_uuid ON stations(uuid);
+
+CREATE TABLE IF NOT EXISTS streams (
+  id              INTEGER PRIMARY KEY AUTOINCREMENT,
+  uuid            TEXT UNIQUE,
+  station_id      INTEGER NOT NULL REFERENCES stations(id) ON DELETE CASCADE,
+  url             TEXT NOT NULL,
+  format          TEXT NOT NULL CHECK (format IN ('mp3','aac','hls','m3u','pls','ogg','unknown')),
+  bitrate         INTEGER,
+  label           TEXT,
+  priority        INTEGER NOT NULL DEFAULT 0,
+  last_checked_at TEXT,
+  last_status     TEXT
+);
+
+CREATE INDEX IF NOT EXISTS idx_streams_station ON streams(station_id);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_streams_uuid ON streams(uuid);
+
+CREATE TABLE IF NOT EXISTS favorites (
+  user_id    INTEGER NOT NULL REFERENCES users(id)    ON DELETE CASCADE,
+  station_id INTEGER NOT NULL REFERENCES stations(id) ON DELETE CASCADE,
+  position   INTEGER NOT NULL DEFAULT 0,
+  created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  PRIMARY KEY (user_id, station_id)
+);
+
+CREATE TABLE IF NOT EXISTS play_history (
+  id         INTEGER PRIMARY KEY AUTOINCREMENT,
+  user_id    INTEGER NOT NULL REFERENCES users(id)    ON DELETE CASCADE,
+  station_id INTEGER NOT NULL REFERENCES stations(id) ON DELETE CASCADE,
+  stream_id  INTEGER          REFERENCES streams(id)  ON DELETE SET NULL,
+  started_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  ended_at   TEXT
+);
+
+CREATE INDEX IF NOT EXISTS idx_history_user ON play_history(user_id, started_at DESC);