feat: Add GLM-4.7-Flash GGUF tensor mapping, MLA attention, and model validation

- TensorNameMapper resolves both llama.cpp (blk.*) and HuggingFace (model.layers.*) naming
- MLA (Multi-Head Latent Attention) with low-rank Q/KV compression (DeepSeek-V2 style)
- Stacked 3D expert tensor support (ffn_gate_exps → per-expert slicing)
- Shared expert + dense layer-0 support (MoeWithShared/Dense/Moe layer types)
- Updated BitNetModelConfig defaults to match GLM-4.7-Flash architecture
- Tensor discovery and model validation harness for GGUF files
- 188 passing tests (14 new)

https://claude.ai/code/session_011nTcGcn49b8YKJRVoh4TaK

crates/ruvllm/src/bitnet/mod.rs

@@ -80,7 +80,10 @@ pub use rlm_embedder::{
     RlmEmbeddingResult,
 };
 pub use rlm_refiner::{RefinementResult, RefinementStepMetrics, RlmRefiner, RlmRefinerConfig};
-pub use backend::{BitNetBackend, BitNetModelConfig};
+pub use backend::{
+    BitNetBackend, BitNetModelConfig, ModelValidation, TensorDiscoveryReport, TensorEntry,
+    TensorGroup,
+};
 pub use expert_cache::{
     ExpertBatch, ExpertCache, ExpertCacheConfig, ExpertCacheStats, EvictionPolicy,
     MoeBatchScheduler, NullPrefetcher, Prefetcher,