fix(tui): address review feedback

ui-tui/src/__tests__/textInputWrap.test.ts

@@ -42,9 +42,10 @@ describe('input metrics helpers', () => {
     expect(inputVisualHeight('one\ntwo', 40)).toBe(2)
   })
 
-  it('reserves a stable transcript scrollbar gutter for composer width', () => {
+  it('reserves gutters without exceeding the physical terminal width', () => {
     expect(stableComposerColumns(100, 3)).toBe(93)
-    expect(stableComposerColumns(10, 3)).toBe(20)
+    expect(stableComposerColumns(10, 3)).toBe(3)
+    expect(stableComposerColumns(6, 3)).toBe(1)
   })
 })
 

ui-tui/src/lib/inputMetrics.ts

@@ -54,9 +54,9 @@ export function inputVisualHeight(value: string, columns: number) {
 }
 
 export function stableComposerColumns(totalCols: number, promptWidth: number) {
-  // totalCols is the terminal width. Reserve:
+  // Physical render/wrap width. Reserve:
   // - outer composer paddingX={1}: 2 columns
   // - transcript scrollbar gutter + marginLeft: 2 columns
   // - prompt prefix width
-  return Math.max(20, totalCols - promptWidth - 4)
+  return Math.max(1, totalCols - promptWidth - 4)
 }