72544278f1
Gated WebP encoding behind OMP_NO_WEBP environment variable so that local llama.cpp vision models (which use the STB library that lacks WebP decoding support) can accept browser snapshots without returning HTTP 400. Upstream reference: cline/cline PR #9837 (https://github.com/cline/cline/pull/9837) implements a similar workaround for the same llama.cpp STB WebP incompatibility.