Anti-aliased VLW fonts using Inter

[theNailz]

Summary

• Replace bitmap fonts (1/2/4) with smooth anti-aliased VLW fonts generated from Inter Regular at 10/14/19pt
• Font 7 (7-segment) kept as-is for clock displays
• New fonts.h abstraction layer with setFont() helper — centralizes all font selection
• Python generator script (scripts/generate_vlw_fonts.py) for reproducible font builds from TTF source
• Character set: printable ASCII + degree symbol (96 glyphs)

Builds on top of the LovyanGFX migration (Keralots#37). Will be included when lovyan-gfx merges upstream.

Flash usage (on top of LovyanGFX)

Board	Before	After
S3	69.1%	71.5%
CYD	66.7%	68.9%
C3	65.3%	70.5%

Test plan

• All three environments build clean
• Flashed and verified on S3 — text renders with anti-aliased Inter font
• Clock mode Font 7 (7-segment) still works correctly
• Verify CYD
• Verify C3
• Fine-tune text positioning if needed (VLW metrics differ slightly from bitmap fonts)

[theNailz]

Looks solid overall — the VLW font pipeline and setFont abstraction are clean. Two things:

1. Type mismatch with headless PR
setFont() in fonts.h takes lgfx::LGFX_Device&, but PR #1 (headless C3) changes the global tft from LGFX_Device& to LovyanGFX& (the base class, needed for sprite polymorphism). If both PRs land, setFont(tft, ...) won't compile. The fix is simple — change the parameter to lgfx::LovyanGFX& — but worth noting so merge order doesn't bite you.

2. Font 6 → FONT_LARGE regression
One callsite previously used tft.setTextFont(compact ? 4 : 6) — Font 6 is noticeably larger than Font 4. After this PR both branches map to FONT_LARGE (Inter 19pt, which replaced Font 4). The non-compact path now uses a smaller font than before. If that layout was tight on space it might be fine, but if the larger font was intentional you'd want a FONT_XLARGE level or a bigger Inter size.