Fixed UI inconsistencies and added logic to handle unit types in the product list and form. Also added a call to toggle the stock input visibility on page load based on the default unit type.

migrate.py

@@ -0,0 +1,23 @@
+import sqlite3
+
+DB_FILE = 'db/pos_database.db'
+
+def upgrade_db():
+    try:
+        with sqlite3.connect(DB_FILE) as conn:
+            # Add stock column
+            conn.execute("ALTER TABLE products ADD COLUMN stock REAL DEFAULT 0")
+            print("Successfully added 'stock' column.")
+            
+            # App.py also expects unit_type, adding it to prevent future headaches
+            conn.execute("ALTER TABLE products ADD COLUMN unit_type TEXT DEFAULT 'unit'")
+            print("Successfully added 'unit_type' column.")
+            
+            conn.commit()
+            print("Migration complete. Your data is intact.")
+            
+    except sqlite3.OperationalError as e:
+        print(f"Skipped: {e}. (This usually means the columns already exist, so you're fine).")
+
+if __name__ == '__main__':
+    upgrade_db()