ClearFormSelectionRects method

ClearFormSelectionRects empties the list returned by FormSelectionRects so the next reported rectangle starts a fresh accumulation

Call it whenever the focused field changes or before repainting selection overlays to avoid drawing stale rectangles

• The OnFormSelectionRect event keeps firing for new rectangles after the clear
• This operates only on the copied rectangle list; the native selection itself is untouched

Pdf1.ClearFormSelectionRects;
PdfView1.Invalidate;