Upgrade to Angular 19, Remove Vulnerabilities, and Migrate to Signals & Standalone Components

[piyushsinghgaur1]

This task involves addressing existing security vulnerabilities by upgrading the application to Angular 19. As part of the upgrade, refactor the codebase to adopt Angular Signals for state management and migrate from NgModules to standalone components where applicable.
The goal is to improve security, performance, and long-term maintainability while aligning the project with modern Angular best practices.