Text is not correctly rendered on Shapes

**Current state**

in `org.apache.poi.sl.draw.DrawTextParagraph`
in method `protected double getWrappingWidth(boolean firstLine, Graphics2D graphics)`

- Indents are correctly subtracted
- Margins too
- Line (the border) width is unaccounted for

Result:
- line breaks are wrong/inconsistent with actual PowerPoint
- Worst cases: text is rendered over the border (e.g. JPG/PNG export)

**To be state**

- Powerpoint has an implicit margin which is 0.5 of the border line width
- getWrappingWidth should account for the line width to get the actual canvas size it is drawing to

Start in org.apache.poi.sl.draw.DrawTextParagraph, specifically getWrappingWidth(boolean firstLine, Graphics2D graphics). Review how indents and margins are subtracted, then account for PowerPoint’s implicit margin based on half the border line width. Done means rendered line breaks match PowerPoint and text no longer overlaps the border in JPG/PNG exports.

Written by the indexing model from the issue text.