[FEATURE] TUI queue management for messages sent during active task — view, delete, reorder, interrupt

Feature Request

When a message is sent while Claude Code is actively working, it gets silently queued. There is currently no UI to:

• See what messages are queued
• Delete a queued message before it runs
• Interrupt Claude with a specific queued message immediately (promoting it to the front)
• Reorder queued messages

This is a significant UX gap compared to Cursor, which surfaces pending messages in the UI and lets the user manage them.

Current Behavior

• Messages typed during active execution are queued (#29224, #30677 related)
• No visibility into the queue in the TUI
• No way to cancel a queued message without waiting for current task to finish
• Docs claim Enter interrupts mid-task, but it only queues (#36326)

Desired Behavior

• TUI shows a visible queue of pending messages while Claude is working
• Keyboard shortcut or UI control to delete a pending message from the queue
• Keyboard shortcut to "interrupt now with this message" — stops current task and runs selected queued message immediately
• Works in both terminal TUI and VS Code extension

Why This Matters / Cursor Parity

Cursor surfaces the message queue prominently and lets users interrupt or discard pending messages mid-task. This is a core part of the human-in-the-loop control model. Without it, users either:

1. Have to wait for the full task to finish before correcting course
2. Hit Escape (cancels everything) with no way to selectively manage the queue

Related Issues

• #29224 — Side-channel responses for queued messages
• #30677 — VS Code queued message support
• #36326 — Enter queues instead of interrupts (docs bug)
• #34835 — Queue up messages feature request