[Feat] Add Animations When Switching Between Screens

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**Is your feature request related to a problem? Please describe.**
The current screen transitions in the app are abrupt and lack smoothness, which can make the user experience feel less polished. Adding animations would enhance the visual appeal and usability.

**Describe the solution you'd like**
Implement smooth and visually appealing animations when navigating between screens in the app. Possible animation styles include:
Slide Transition: The new screen slides in from the right, while the current screen slides out to the left.
Fade Transition: The current screen fades out, and the new screen fades in.
Scale Transition: The new screen scales up as it becomes visible.
Animations should be consistent and responsive to user interactions.

No files, tests, or navigation entry points are named. Start by locating the Flutter screen-navigation code and reviewing how transitions currently occur; done means screen changes use a consistent, responsive animation matching an agreed style.

Written by the indexing model from the issue text.