feat: add description field and migration support

migrate.py

@@ -0,0 +1,33 @@
+import sqlite3
+import sys
+
+
+def migrate_database():
+    try:
+        # Connect to the database
+        db = sqlite3.connect("pet_pictures.db")
+        cursor = db.cursor()
+
+        # Check if description column exists
+        cursor.execute("PRAGMA table_info(pet_pictures)")
+        columns = [column[1] for column in cursor.fetchall()]
+
+        if "description" not in columns:
+            print("Adding description column to pet_pictures table...")
+            cursor.execute("ALTER TABLE pet_pictures ADD COLUMN description TEXT")
+            db.commit()
+            print("Migration completed successfully!")
+        else:
+            print("Description column already exists. No migration needed.")
+
+    except sqlite3.Error as e:
+        print(f"An error occurred: {e}")
+        sys.exit(1)
+    finally:
+        if db:
+            db.close()
+
+
+if __name__ == "__main__":
+    print("Starting database migration...")
+    migrate_database()