[Feature Request] Mobile: Implement instant interrupt and background command support parity with desktop

Bug Description
Mobile: Stop/interrupt has latency and doesn't reliably reach the model promptly, unlike desktop Esc (instant). ▎ When a foreground Bash command is blocking the session, desktop users can press Esc (instant interrupt) or Ctrl+B (background it). On mobile, the Stop button seems delayed / doesn't register as immediately, and there's no Ctrl+B equivalent — so mobile users get trapped waiting on long-running foreground commands (deploys, watches) with no clean escape. ▎ Requests: (a) make mobile Stop as responsive as desktop Esc; (b) a mobile-friendly "send this command to background" gesture (Ctrl+B equivalent).

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.211
• Feedback ID: da67c55d-b15a-433c-8008-3fc1e7de58e8

Errors

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