Block help shortcut while editing queued prompts

[warp-dev-github-integration]

Summary

• prevent the Agent View ? help shortcut from matching while the queued-prompt inline editor is open
• let the queued editor handle ? as ordinary text input
• add key-dispatch regression coverage for an empty regular input and non-empty queued prompt

Testing

• CARGO_BUILD_JOBS=1 cargo nextest run --manifest-path /workspace/warp/Cargo.toml -p warp -E 'test(question_mark_is_inserted_while_editing_queued_prompt)'
• CARGO_BUILD_JOBS=1 cargo nextest run --manifest-path /workspace/warp/Cargo.toml -p warp -E 'test(terminal::view::queued_prompts_tests)'
• cargo fmt --manifest-path /workspace/warp/Cargo.toml --package warp --check
• CARGO_BUILD_JOBS=1 cargo clippy --manifest-path /workspace/warp/Cargo.toml -p warp --lib --tests -- -D warnings

Conversation: https://staging.warp.dev/conversation/e12a84a9-a4f0-4cb1-8a34-c3472da16ba4
Run: https://oz.staging.warp.dev/runs/019f5d59-8264-7d73-94f3-043ac62ca37a

Co-Authored-By: Oz oz-agent@warp.dev

This PR was generated with Oz.