Bug: Incorrect Line Boundary for Offsets at Line Start

When codepointPosition is at the boundary between two lines (i.e., equal to the start of the second line, which is also the end of the first line), and the first line does not end with a hard line break, line.hardLineBreakStart for the first line is equal to line.allLineTextRange.end.

Because of the >= operator in line.hardLineBreakStart >= codepointPosition, the first line will match codepointPosition, and getLineBoundary will incorrectly return the boundary of the first line instead of the second line.

Counter-Example:

For a paragraph with text "Hello World" wrapped into two lines:

• Line 1: start = 0, end = 6, hardLineBreakStart = 6 ("Hello ")
• Line 2: start = 6, end = 11, hardLineBreakStart = 11 ("World")

If we query getLineBoundary(6) (the index of 'W'):

• For Line 1: 0 <= 6 and 6 >= 6 are both true, so it matches Line 1 and returns [0, 6).
• However, index 6 is 'W', which belongs to Line 2. It should return [6, 11).

Proposed Test Case:

test('getLineBoundary handles soft-wrapped multiline text correctly at line boundaries', () {
  final paragraphStyle = WebParagraphStyle(
    fontFamily: 'Arial',
    fontSize: 20,
  );
  const text = 'Hello World';
  final builder = WebParagraphBuilder(paragraphStyle);
  builder.addText(text);
  final WebParagraph paragraph = builder.build();
  paragraph.layout(const ui.ParagraphConstraints(width: 60)); // Force wrap between Hello and World

  final ui.TextRange boundary = paragraph.getLineBoundary(6);
  expect(boundary, const ui.TextRange(start: 6, end: 11));
});

      if (line.allLineTextRange.start <= codepointPosition &&
          (line.allLineTextRange.end > codepointPosition ||
           (line.lineNumber == lines.length - 1 && line.allLineTextRange.end == codepointPosition))) {
        return ui.TextRange(start: line.allLineTextRange.start, end: line.hardLineBreakStart);