docs: add Qwen3.8-27B model

[ai-bankofai]

Summary

• Add English and Chinese Qwen3.8-27B model documentation.
• Add Qwen3.8-27B to the pricing table and Qwen navigation.
• Document standard pricing: 0.22 input, 0.22 cache write, 0.022 cache read, and 1.60 output.
• Bump the documentation version from 1.3.23 to 1.3.24.

Validation

• yarn build (English and Chinese builds completed successfully; existing unrelated broken-link warnings remain).