feat(tui): add clear command

[aqilaziz]

Description

Adds a clear command to the TUI so users can clear previous command output and reset the output scroll position.

Fixes #4

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Chore / Refactor

Related issues

• Issue: Add clear command in TUI #4
• Related PRs: none

How Has This Been Tested

• Unit tests: cargo test
• Integration tests: covered by cargo test
• Manual steps: cargo fmt --check; cargo build --release
• Platform tested on: Windows

Checklist

• I have read the CONTRIBUTING.md and followed the repo guidelines.
• Code builds locally (cargo build --release)
• All tests pass (cargo test)
• New and existing tests cover my changes
• I added/updated documentation where applicable
• I updated CHANGELOG or release notes if needed

CI and Performance Notes

• CI status: expected to pass.
• Performance impact: none expected.

Screenshots or Logs

N/A

Release Notes

• Release type: minor
• Notes for release manager: TUI now supports a clear command to clear command output.

[SickleFire]

Hello @aqilaziz thank you for contributing to this project, Welcome to mvis