v0.1.2

Fixed bug in add.php where purchase_url was incorrectly bound as an integer.
Corrected the PLA-ID format issue in add.php by ensuring the unique_id is generated properly as PLA-12345.
Added Google Fonts (Roboto) for smoother font appearance in navigation.php and footer.php.
Enhanced navbar and footer with shadows, font weight adjustments, and better padding.
Added session check in footer.php for additional security.