Fullscreen/NO_FLICKER renderer: Option+Delete (Meta+Backspace) word-delete stops working — classic renderer unaffected

Description

In the prompt input box, Option+Delete (macOS sends Meta+Backspace, ESC + 0x7f) deletes the previous word in the classic renderer, but is a no-op in the fullscreen / flicker-free (alt-screen) renderer.

Ctrl+W (backward-kill-word) works in both renderers, so the fullscreen input path appears to specifically drop the Meta+Backspace escape sequence.

This was isolated by toggling only the renderer (/tui default ↔ /tui fullscreen) with no other change.

Steps to reproduce

1. macOS + Warp (Option configured to send Meta/Esc+, which is Warp's default).
2. /tui default (classic): type a few words, press Option+Delete → previous word is deleted. ✅
3. /tui fullscreen (flicker-free): type a few words, press Option+Delete → nothing happens. ❌
4. Ctrl+W deletes the previous word in both modes.

(Also reproducible by starting with CLAUDE_CODE_NO_FLICKER=1 / "tui": "fullscreen" instead of the /tui command.)

Expected behavior

Option+Delete deletes the previous word in fullscreen mode too (parity with the classic renderer).

Actual behavior

Option+Delete is a no-op in the fullscreen / NO_FLICKER renderer only.

Environment

• Claude Code: 2.1.186
• OS: macOS (Darwin 25.5.0)
• Terminal: Warp (v0.2026.06.17, stable)

Related issues

• #50503 (closed / completed) — Fullscreen TUI: Cmd+Left/Right cursor jump not working. Same class of bug (an editing/navigation key sequence handled by the classic renderer but missed by the fullscreen alt-screen input path); already fixed. This report is the Option+Delete / Meta+Backspace counterpart.
• #33287 / #16830 (closed) — earlier "Option+Delete stopped working" reports, but not framed as renderer-specific. The new information here is that the breakage is specific to the fullscreen / NO_FLICKER renderer — the classic renderer handles Option+Delete correctly.

Notes

• Not fixable via keybindings.json — text-editing operations (delete-word) are not exposed as bindable keybinding actions.