feat(reader): autonomous Wikipedia import and reading with media, tables and settings

app/database.py

@@ -79,12 +79,18 @@ def _migrate(conn: sqlite3.Connection):
         current_chapter INTEGER DEFAULT 0,
         current_position REAL DEFAULT 0,
         total_words INTEGER DEFAULT 0,
+        cover_url TEXT DEFAULT '',
         created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
         updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
         FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
     );
     """)
 
+    # Safe migration: ensure cover_url column exists in books
+    books_cols = {row[1] for row in conn.execute("PRAGMA table_info(books)").fetchall()}
+    if "cover_url" not in books_cols:
+        conn.execute("ALTER TABLE books ADD COLUMN cover_url TEXT DEFAULT ''")
+
     # --- Deduplicate vocabulary_cards (case-insensitive) and enforce UNIQUE index ---
     dup_rows = conn.execute("""
         SELECT user_id, lower(trim(term)) as clean_term, COUNT(*) as cnt