"Fix #10: Unify settings system with reusable component"

[Dheemanth07]

Summary

This PR solves issue #10 by implementing a reusable Settings component and applying it across all main pages to ensure UI consistency.

Key Changes

• Created src/components/Settings.js: Having global settings UI and toggle logic.
• Refactored Pages: Updated DailyScheduler, FocusTimer, HabitTracker, TaskManager, KnowledgeBase, and QuickLinks to use the new component.
• Fixed UI/UX:
  • The "Settings" gear is now fixed to the top-right of the screen on all pages.
• Renamed Title: Changed the menu header to "Settings" to clearly distinguish it from page-specific controls (like the timer duration).

Notes for Reviewers

• Placeholders: The menu items (Display, Account, Log Out) are currently set to # (placeholders). I established the structure so these can be easily linked to real routes or authentication logic in a future update.
• Local vs. Global: I verified that the local settings (e.g., inside the Focus Timer card) function independently of this new global menu.