Add flag to disable mouse/scroll capture in interactive prompts

Problem

Claude Code's TUI (Ink2) enables SGR mouse tracking during interactive prompts (e.g., permission dialogs, multi-choice selections). This causes scroll gestures to navigate prompt options instead of scrolling terminal history.

This is particularly painful for remote/mobile workflows:

• Termius (iPhone) over SSH + tmux: Swiping up to scroll terminal history instead triggers prompt option cycling
• tmux copy mode (Ctrl-b [) is the only workaround, and it's clunky on mobile
• After the prompt resolves, scrollback works normally — but during the prompt, scroll is hijacked

Environment

• Client: Termius on iPhone, connecting via SSH over Tailscale
• Server: macOS with tmux (mouse mode off in tmux config)
• Claude Code captures mouse regardless of tmux's set -g mouse off

Request

Add a way to disable mouse/scroll capture in interactive prompts:

• A CLI flag like --disable-mouse
• Or an environment variable like CLAUDE_CODE_DISABLE_MOUSE=1
• Or a setting in ~/.claude/settings.json

Interactive prompts should support keyboard-only navigation (arrow keys + Enter already work) without needing to capture mouse events.

Workaround

Currently using Ctrl-b [ (tmux copy mode) to scroll past active prompts, but this is not viable on mobile keyboards.