[FEATURE] Add keybind for navigating to previous/next message (like OpenCode's messages_previous)

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

There is no way to navigate to previous messages/prompts within a Claude Code session. Scrolling through the terminal buffer is the only option, which breaks down entirely in tmux and is cumbersome in long sessions.

Proposed Solution

Add configurable keybinds for messages_previous and messages_next — similar to OpenCode's implementation — that jump the cursor/view directly to previous and next messages in the conversation. These should be remappable in Claude Code's keybind settings.

Alternative Solutions

_No response_

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

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Additional Context

_No response_