Add comprehensive comments to all source files and expand documentation

init_db.py

@@ -1,12 +1,25 @@
+"""
+init_db.py
+==========
+Standalone script to create the SQLite database tables.
+
+Run this once inside the container after deployment:
+    python init_db.py
+
+Or use the Flask CLI command:
+    flask --app app init-db
+"""
+
 import os
 import sys
 
-# Ensure project root is importable
+# Ensure the project root is on sys.path so `from app import app` works.
 sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
 
 from app import app
 from models import init_db
 
+# Use the configured database path and create tables.
 with app.app_context():
     init_db()
     print(f"Database initialized at {app.config['DATABASE']}")