The family matcher required a `v4` marker, so `deepseek-flash` requests
went unpriced. Accept `deepseek` as an alternative marker — proxy
spellings like `deepseek/deepseek-flash` land too, while foreign
flash-named models (gemini-2.0-flash) still match no family. The stats
board's price-list label and both locales' cost tooltip name the new
model beside deepseek-v4.1-flash.