[FEATURE] End game summary when completing all the scenarios

[fabiosirna]

Feature Description

Implement a "Congratulation screen" or "End game summary" that triggers automatically once a user finishes the final scenario.

Problem Statement

This morning I completed all the 135 scenario and...nothing happened. I was expecting a congratulation screen or similar.
Reaching the end feels a bit....unfinished:

• user stays on the final exercise page
• next button is active but lead to nowhere
• no feedback or summary of the current progess

Proposed Solution

When the last available scenario is completed, the app should redirect the user to a dedicated screen that should include:

• a congratulations message, a clear visual celebration of completing the curriculum.
• progress summary: a recap of total XP earned, accuracy, or time spent (something similar to the profile)
• next steps, suggestions on what to do next to keep the habit alive, such as: "Try Arcade Mode to test your speed" or "Complete the Daily Quests." or "Review exercises."

Priority

• Critical - blocks my usage
• High - significantly improves experience
• Medium - nice to have
• Low - minor improvement