Feature/scratchpad widget

[AwadhDhoot23]

Summary

Added a new persistent "Scratchpad" widget to the dashboard layout. This allows users to quickly jot down notes directly in their new tab. It includes:

• Local storage persistence so notes are never lost on reload
• Smart auto-list generation (- , * , or 1. ) that automatically indents the next line
• Dedicated "Copy" and "Clear All" action buttons with interactive hover states
• Seamless glassmorphism styling perfectly matched to the existing theme

Closes #139

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor (no behavior change)
• Chore / tooling
• UI polish

Screenshots / Screen Recording

How to Test

1. Run the project locally (npm run dev).
2. Type some text into the new Scratchpad below the Tasks section.
3. Refresh the page to verify the text persists.
4. Try typing 1. followed by Enter to test the auto-list generation.
5. Click the Copy button, paste elsewhere to verify, and use the Clear button to empty the pad.

Checklist

• I linked the related issue, if one exists.
• I assigned myself before opening the PR, if required.
• npm run lint passes.
• npm run typecheck passes.
• npm run build succeeds.
• I reviewed my own changes before requesting review.
• I did not change unrelated files.
• I updated documentation if needed.