Add `lodepng`

[MeteorsLiu]

Use write-formula SKILL to add https://github.com/lvandeve/lodepng to llarhub

[MeteorsLiu]

/code

[fennoai]

Added the lodepng formula in PR #7.

Files created:

• lvandeve/lodepng/versions.json — module metadata
• lvandeve/lodepng/20260119/Lodepng_llar.gox — build formula

Since lodepng has no build system (no CMake/autotools), the formula compiles lodepng.cpp directly with g++ and archives it with ar into liblodepng.a, then installs the header. Version 20260119 follows lodepng's date-based versioning.