Add Vim-style navigation keys (k/j, Ctrl+U/Ctrl+D) to the transcript overlay pager

What feature would you like to see?

Please add Vim-style navigation to the transcript overlay pager:

• k: scroll up one line
• j: scroll down one line
• Ctrl+U: page up
• Ctrl+D: page down

Keep existing arrow/PgUp/PgDn/Space/Home/End behavior unchanged.
This would make transcript navigation consistent with common terminal/Vim muscle memory without disrupting current users.

Additional information

_No response_