feat: add delete-test command with confirmation

[d-claro]

What was done

• Added delete-test command to permanently delete a test case from the database
• Added confirmation step before deletion to prevent accidental deletions
• Added deletion event to the project history
• Added Delete Test Case option to the Test Cases submenu

New Command

• delete-test TC-001 — deletes a test case after confirmation

How it works

• Shows the test case details before asking for confirmation
• If confirmed, removes the test case from test_cases.json
• Logs the deletion event in history.json automatically
• If cancelled, nothing is changed

Notes

• This action is permanent and cannot be undone
• The deletion is logged in the project history for reference
• Open for suggestions and feedback from the team.