DeepSeek V4 Updated

Deepseek-v4-flash now defaults to DeepSeek-V4-Flash-0731, and deepseek-v4-pro to DeepSeek-V4-Pro-0813.

Both versioned and unversioned IDs remain supported. Pricing now matches DeepSeek’s official cache-hit, cache-miss, output, and time-based rates.

Peak hours are 09:00–12:00 and 14:00–18:00 Beijing Time; all other hours are 50% off. No API or client changes are required.