Feature request: navigate between prompts in context with Ctrl+PgUp / Ctrl+PgDn

In many terminals and chat clients, Ctrl+PgUp / Ctrl+PgDn navigate through previous/next items in history.

It would be useful in Kimi Code CLI to be able to jump between user prompts in the current session context using these keys, especially during long sessions where the context contains many tool calls and assistant responses between user messages.

Proposed behavior

• Ctrl+PgUp: jump to the previous user prompt in the context.
• Ctrl+PgDn: jump to the next user prompt in the context.
• Optional: also support Alt+Up / Alt+Down for keyboards without dedicated PgUp/PgDn keys.

Why this helps

• Faster navigation in long sessions without manually scrolling.
• Easier to review conversation flow and refer back to earlier instructions.
• Aligns with common terminal/editor keybindings.

Scope

This is a TUI/keyboard-navigation enhancement. It does not change model behavior or context content.

No file or test is named in the issue. Start by locating the TUI keyboard-input handling and the representation of user prompts in the current session context. Done means Ctrl+PgUp and Ctrl+PgDn move between user prompts without changing context content, with the optional Alt+Up/Alt+Down behavior addressed explicitly.