Two 0.87.5 follow-ups:
1. Pin spawn_blocking dispatch: new current_thread runtime test runs
analyze() on a 6 MP image while a counter task ticks every 5 ms.
Without spawn_blocking the counter is starved (0 ticks); with it
the runtime stays responsive (≥2 ticks). Mutation-confirmed.
2. Warn on Undecodable fallback: five fallback paths in prepare_analysis
now emit a tracing::warn! with dimensions so a JPEG encoder
regression isn't indistinguishable from "the page was just garbage."
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
95de02f583