feat(tui): improve editor Ctrl/Alt word and line deletion shortcuts

- Add Ctrl+W for word deletion (stops at whitespace/punctuation)
- Add Ctrl+U for delete to start of line (merges with previous line at col 0)
- Change Ctrl+K from delete entire line to delete to end of line (merges with next line at EOL)
- Add Option+Backspace support in Ghostty (maps to Ctrl+W via ESC+DEL sequence)
- Cmd+Backspace in Ghostty works as Ctrl+U (terminal sends same control code)
- Update README and CHANGELOG with new keyboard shortcuts

Fixes #2, Fixes #3

packages/tui/test/key-tester.ts

@@ -0,0 +1,91 @@
+#!/usr/bin/env node
+import { ProcessTerminal } from "../src/terminal.js";
+import { type Component, TUI } from "../src/tui.js";
+
+/**
+ * Simple key code logger component
+ */
+class KeyLogger implements Component {
+	private log: string[] = [];
+	private maxLines = 20;
+	private tui: TUI;
+
+	constructor(tui: TUI) {
+		this.tui = tui;
+	}
+
+	handleInput(data: string): void {
+		// Convert to various representations
+		const hex = Buffer.from(data).toString("hex");
+		const charCodes = Array.from(data)
+			.map((c) => c.charCodeAt(0))
+			.join(", ");
+		const repr = data
+			.replace(/\x1b/g, "\\x1b")
+			.replace(/\r/g, "\\r")
+			.replace(/\n/g, "\\n")
+			.replace(/\t/g, "\\t")
+			.replace(/\x7f/g, "\\x7f");
+
+		const logLine = `Hex: ${hex.padEnd(20)} | Chars: [${charCodes.padEnd(15)}] | Repr: "${repr}"`;
+
+		this.log.push(logLine);
+
+		// Keep only last N lines
+		if (this.log.length > this.maxLines) {
+			this.log.shift();
+		}
+
+		// Request re-render to show the new log entry
+		this.tui.requestRender();
+	}
+
+	render(width: number): string[] {
+		const lines: string[] = [];
+
+		// Title
+		lines.push("=".repeat(width));
+		lines.push("Key Code Tester - Press keys to see their codes (Ctrl+C to exit)".padEnd(width));
+		lines.push("=".repeat(width));
+		lines.push("");
+
+		// Log entries
+		for (const entry of this.log) {
+			lines.push(entry.padEnd(width));
+		}
+
+		// Fill remaining space
+		const remaining = Math.max(0, 25 - lines.length);
+		for (let i = 0; i < remaining; i++) {
+			lines.push("".padEnd(width));
+		}
+
+		// Footer
+		lines.push("=".repeat(width));
+		lines.push("Test these:".padEnd(width));
+		lines.push("  - Option/Alt + Backspace".padEnd(width));
+		lines.push("  - Cmd/Ctrl + Backspace".padEnd(width));
+		lines.push("  - Regular Backspace".padEnd(width));
+		lines.push("=".repeat(width));
+
+		return lines;
+	}
+}
+
+// Set up TUI
+const terminal = new ProcessTerminal();
+const tui = new TUI(terminal);
+const logger = new KeyLogger(tui);
+
+tui.addChild(logger);
+tui.setFocus(logger);
+
+// Handle Ctrl+C for clean exit
+process.on("SIGINT", () => {
+	tui.stop();
+	console.log("\nExiting...");
+	process.exit(0);
+});
+
+// Start the TUI
+tui.start();