Add test suite covering:
- Model loading validation (config, dtype, model_type checks)
- Audio preprocessing (mono/stereo, normalization, resampling, padding)
- Tokenization (token IDs, attention masks, embeddings, vocab)
- Inference pipeline (greedy decoding, temperature, top-k, KV cache)
- Weight initialization (Linear, LayerNorm, Embedding)
- Model validation utility module

Signed-off-by: Srikanth Patchava <[email protected]>

Add validation check for torch_dtype string before calling getattr().
Previously, an invalid dtype string like 'invalid_dtype' would cause
an unhelpful AttributeError. Now raises a clear ValueError with the
list of supported dtypes (float16, float32, bfloat16).

Signed-off-by: Srikanth Patchava <[email protected]>