[codex] fix editor input regressions

[agjs]

Summary

• fix editor-backed /exit and /quit shutdown plus overlay input ownership
• restore / palette and @ picker triggers in default editor mode
• make editor wrapping/clipping terminal-cell aware and fix redo undoability

Root cause

The multiline editor became the default TTY input owner, but parts of the REPL still assumed readline-owned input. Some editor rendering code also reported clamped row counts while returning unclipped frames.

Validation

• bun run validate

[gemini-code-assist]

Code Review

This pull request enhances the terminal editor by implementing terminal-cell-width-based wrapping (supporting wide CJK characters and emojis), adding visual clipping with scroll indicators for over-tall lines, and introducing input suspension when overlays like the command palette or file picker are active. It also fixes an undo/redo stack issue where redos could not be undone. Feedback was provided to extend the wide character detection in isWideCodePoint to include CJK characters in Plane 2 and Plane 3.

Important

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[gemini-code-assist]

The isWideCodePoint function does not account for CJK characters in Plane 2 (Supplementary Ideographic Plane, 0x20000..0x2FFFF) and Plane 3 (Tertiary Ideographic Plane, 0x30000..0x3FFFF). These characters are also wide and should have a terminal width of 2. We should update the check to include these ranges.

Suggested change

	function isWideCodePoint(cp: number): boolean {
	return (
	cp >= 0x1100 &&
	(cp <= 0x115f ||
	cp === 0x2329 ||
	cp === 0x232a ||
	(cp >= 0x2e80 && cp <= 0xa4cf && cp !== 0x303f) ||
	(cp >= 0xac00 && cp <= 0xd7a3) ||
	(cp >= 0xf900 && cp <= 0xfaff) ||
	(cp >= 0xfe10 && cp <= 0xfe19) ||
	(cp >= 0xfe30 && cp <= 0xfe6f) ||
	(cp >= 0xff00 && cp <= 0xff60) ||
	(cp >= 0xffe0 && cp <= 0xffe6))
	);
	}
	function isWideCodePoint(cp: number): boolean {
	return (
	(cp >= 0x1100 &&
	(cp <= 0x115f ||
	cp === 0x2329 ||
	cp === 0x232a ||
	(cp >= 0x2e80 && cp <= 0xa4cf && cp !== 0x303f) ||
	(cp >= 0xac00 && cp <= 0xd7a3) ||
	(cp >= 0xf900 && cp <= 0xfaff) ||
	(cp >= 0xfe10 && cp <= 0xfe19) ||
	(cp >= 0xfe30 && cp <= 0xfe6f) ||
	(cp >= 0xff00 && cp <= 0xff60) ||
	(cp >= 0xffe0 && cp <= 0xffe6))) ||
	(cp >= 0x20000 && cp <= 0x3ffff)
	);
	}