Fix rendering issues where content from previous screens bled through when switching between views of different heights/widths: - Pad every line to full terminal width (ANSI-aware) so shorter lines overwrite leftover content from previous renders - Track terminal height via WindowSizeMsg and pad between content and footer to fill the screen - Send tea.ClearScreen on all screen transitions for height changes - Fix panic in transfer completion when routing number is < 4 chars Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>