Cleanup Step 2: Archive Lineage P code, fix broken imports
- Move dead dsv4/ modules to dsv4/_archive/ (52 files)
- model/{dsv4,mtp,layer,layer_schedule}
- layers/{embedding,attention,ffn,norm} (kept linear,mhc,router,moe,shared_expert,grouped_linear - live)
- cache/*, kernels/cache/*, kernels/indexer/{csa_indexer,score_topk,compute_valid_lens}
- kernels/router/{nvfp4_fused_router,dense_router_decode_kernel,dense_router_prefill}
- ops/{topk,topk_select,rope,router}, loader/{hf_checkpoint,layout_convert}
- reference/{attention,compressor,csa_attention,moe_pipeline}
- kernels/compressor/{compress_tail,csa_hca}
- Restore dsv4/ops/{router,custom_ops}.py (needed by live layers)
- Fix dsv4/kernels/{indexer,compressor,attention}/__init__.py (removed broken imports)
- Remove preload_all() from loader.py (dead, referenced nonexistent .cu file)
- Fix loader.py docstring (fused_amax_quantize_nvfp4 → quantize_nvfp4_from_buffer)
- Move broken tests to tests/e2e_archive/
- test_fused_router, production_values_test, e2e/{one_layer,model_construction,csa_hca}
- vLLM has 0 imports of dsv4 (Step 0 confirmed)
biondizzle
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