fix(tui): remove backslash input buffering (#1037)

Instead of buffering `\` and waiting for the next key, let it be
inserted immediately. On Enter, check if preceded by `\` and treat as
newline.

Removed backslash handling from the Input component entirely.

packages/tui/src/components/input.ts

@@ -19,7 +19,6 @@ export class Input implements Component, Focusable {
 	// Bracketed paste mode buffering
 	private pasteBuffer: string = "";
 	private isInPaste: boolean = false;
-	private pendingShiftEnter: boolean = false;
 
 	getValue(): string {
 		return this.value;
@@ -68,22 +67,6 @@ export class Input implements Component, Focusable {
 			return;
 		}
 
-		if (this.pendingShiftEnter) {
-			if (data === "\r") {
-				this.pendingShiftEnter = false;
-				if (this.onSubmit) this.onSubmit(this.value);
-				return;
-			}
-			this.pendingShiftEnter = false;
-			this.value = `${this.value.slice(0, this.cursor)}\\${this.value.slice(this.cursor)}`;
-			this.cursor += 1;
-		}
-
-		if (data === "\\") {
-			this.pendingShiftEnter = true;
-			return;
-		}
-
 		const kb = getEditorKeybindings();
 
 		// Escape/Cancel