fix(tui): trim whitespace-only selection chrome

- clamp selection highlight to real row content so blank drag margins do not render or copy
- keep successful copy actions quiet while preserving usage and failure feedback

ui-tui/packages/hermes-ink/src/ink/selection.test.ts

@@ -0,0 +1,57 @@
+import { describe, expect, it } from 'vitest'
+
+import { cellAt, CellWidth, CharPool, createScreen, HyperlinkPool, setCellAt, StylePool } from './screen.js'
+import {
+  applySelectionOverlay,
+  createSelectionState,
+  getSelectedText,
+  startSelection,
+  updateSelection
+} from './selection.js'
+
+const screenWithText = () => {
+  const styles = new StylePool()
+  const screen = createScreen(10, 3, styles, new CharPool(), new HyperlinkPool())
+
+  setCellAt(screen, 2, 1, { char: 'h', hyperlink: undefined, styleId: screen.emptyStyleId, width: CellWidth.Narrow })
+  setCellAt(screen, 3, 1, { char: 'i', hyperlink: undefined, styleId: screen.emptyStyleId, width: CellWidth.Narrow })
+
+  return { screen, styles }
+}
+
+describe('selection whitespace handling', () => {
+  it('does not copy whitespace-only selections', () => {
+    const { screen } = screenWithText()
+    const selection = createSelectionState()
+
+    startSelection(selection, 0, 0)
+    updateSelection(selection, 9, 0)
+
+    expect(getSelectedText(selection, screen)).toBe('')
+  })
+
+  it('trims outer drag padding while preserving selected content', () => {
+    const { screen } = screenWithText()
+    const selection = createSelectionState()
+
+    startSelection(selection, 0, 1)
+    updateSelection(selection, 9, 1)
+
+    expect(getSelectedText(selection, screen)).toBe('hi')
+  })
+
+  it('does not paint selection background on leading/trailing empty cells or empty rows', () => {
+    const { screen, styles } = screenWithText()
+    const selection = createSelectionState()
+
+    startSelection(selection, 0, 0)
+    updateSelection(selection, 9, 2)
+    applySelectionOverlay(screen, selection, styles)
+
+    expect(cellAt(screen, 0, 0)?.styleId).toBe(screen.emptyStyleId)
+    expect(cellAt(screen, 0, 1)?.styleId).toBe(screen.emptyStyleId)
+    expect(cellAt(screen, 2, 1)?.styleId).not.toBe(screen.emptyStyleId)
+    expect(cellAt(screen, 4, 1)?.styleId).toBe(screen.emptyStyleId)
+    expect(cellAt(screen, 0, 2)?.styleId).toBe(screen.emptyStyleId)
+  })
+})

ui-tui/packages/hermes-ink/src/ink/selection.ts

@@ -842,6 +842,33 @@ export function isCellSelected(s: SelectionState, col: number, row: number): boo
   return true
 }
 
+function rowSelectableContentBounds(screen: Screen, row: number): { first: number; last: number } | null {
+  if (row < 0 || row >= screen.height) {
+    return null
+  }
+
+  const rowOff = row * screen.width
+  let first = -1
+  let last = -1
+
+  for (let col = 0; col < screen.width; col++) {
+    if (screen.noSelect[rowOff + col] === 1) {
+      continue
+    }
+
+    const cell = cellAt(screen, col, row)
+
+    if (!cell || cell.width === CellWidth.SpacerTail || cell.width === CellWidth.SpacerHead || !cell.char.trim()) {
+      continue
+    }
+
+    first = first === -1 ? col : first
+    last = col
+  }
+
+  return first === -1 ? null : { first, last }
+}
+
 /** Extract text from one screen row. When the next row is a soft-wrap
  *  continuation (screen.softWrap[row+1]>0), clamp to that content-end
  *  column and skip the trailing trim so the word-separator space survives
@@ -926,7 +953,7 @@ export function getSelectedText(s: SelectionState, screen: Screen): string {
     joinRows(lines, s.scrolledOffBelow[i]!, s.scrolledOffBelowSW[i])
   }
 
-  return lines.join('\n')
+  return lines.join('\n').trim()
 }
 
 /**
@@ -1049,10 +1076,20 @@ export function applySelectionOverlay(screen: Screen, selection: SelectionState,
   const noSelect = screen.noSelect
 
   for (let row = start.row; row <= end.row && row < screen.height; row++) {
-    const colStart = row === start.row ? start.col : 0
-    const colEnd = row === end.row ? Math.min(end.col, width - 1) : width - 1
+    const bounds = rowSelectableContentBounds(screen, row)
+
+    if (!bounds) {
+      continue
+    }
+
+    const colStart = Math.max(row === start.row ? start.col : 0, bounds.first)
+    const colEnd = Math.min(row === end.row ? end.col : width - 1, bounds.last)
     const rowOff = row * width
 
+    if (colStart > colEnd) {
+      continue
+    }
+
     for (let col = colStart; col <= colEnd; col++) {
       const idx = rowOff + col