[Feature] qwen3_32b_prefill_mixed.py on A3/A5 platforms with good precision & performance

[zhangqi-chen]

Summary

Track the validation and performance of qwen3_32b_prefill_mixed.py on both A3 and A5 platforms. Here "mixed" refers to the mixed (tilelet-aware) programming style.

Motivation / Use Case

1. The mixed-style prefill kernel runs correctly on A3
2. The mixed-style prefill kernel runs correctly on A5
3. Performance on both platforms is benchmarked and maintained at a competitive level
4. Regressions are caught early as the compiler and runtime evolve

Proposed API / Behavior

• Validate numerical correctness on A3
• Validate numerical correctness on A5
• Ensure performance stays competitive with scope-specific implementations