Transcript view lacks internal scrolling — unusable via keyboard, relies on terminal backbuffer

Problem

The Transcript view (Ctrl+O) has no internal scroll handling. It relies entirely on the terminal emulator or multiplexer (e.g., tmux) to scroll the rendered output. This means:

1. No keyboard scrolling at all. Arrow keys, Page Up/Down, and custom keybindings in the Scroll context have no effect. The Scroll context is documented as applying to "fullscreen layout" which doesn't appear to exist in the CLI.

1. Mouse/trackpad scrolling only works indirectly. In tmux with mouse on, trackpad scrolling works but only because tmux is scrolling its own backbuffer — not because Claude Code is handling it. With mouse off (a common tmux config), nothing scrolls at all.

1. Long conversations are inaccessible. Because scrolling depends on the tmux/terminal backbuffer (which has a finite history-limit), earlier parts of a long conversation cannot be reached in the Transcript view.

Expected behavior

The Transcript view should handle scrolling internally, like less or any well-behaved TUI application. It should:

• Support keyboard scrolling (at minimum arrow keys, Page Up/Down)
• Respect the Scroll context keybindings (e.g., ctrl+f/ctrl+b for page scroll, ctrl+u/ctrl+d for half-page)
• Not depend on the terminal's backbuffer for scroll range

Environment

• Claude Code CLI in Alacritty + tmux (also tested in macOS Terminal.app)
• macOS