Add text rendering support via the Windows 3.x ExtTextOut DDI function.
Builds a .FNT v3 font structure from the VGA BIOS 8x16 ROM font
(INT 10h AH=11h), with v3 char table (6-byte entries, absolute offsets)
required by VBESVGA.DRV's BigFontFlags in protected mode. Provides a
full-screen clip rect since STRBLT.ASM unconditionally dereferences
lpClipRect. Tested with both VBESVGA.DRV and S3TRIO.DRV.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>