Improve Log Management: Add Log Deletion, Reverse Timetable Order, and Fix Duplicate Logging Bug

[aljaljak2]

As an Android user, I want to:

• Delete session logs within the app, so that I can free up storage space and remove logs that are no longer needed.
• See the most recent logs first in the timetable, so I can quickly view my latest activity.
• Avoid duplicate activity logs, as some logs are currently recorded 2–3 times instead of once.

Acceptance Criteria

• A UI option (e.g., "Delete All Logs", "Delete single log") is available on the logs screen.
• Deleting logs removes them from local storage and updates the UI.
• The timetable/log list displays entries in reverse chronological order (most recent first).
• Each user activity is logged only once — duplicate entries no longer appear.