…t loading, and model loader

674 squashed commits: reorganize turbomind directory structure, refactor
weight loading to support heterogeneous weight data types, add WeightFormat
enum, replace BaseOutputModel/TextModelLoader with unified ModelLoader,
eliminate data_format threading from Linear, and remove dead code.

- Move dequant/transform utilities from _base.py into linear.py as the
  canonical home for all Linear operations
- Unify _ensure_compatible_formats and dequant_mixed into a single
  dequant_mixed function that triggers on any format diversity
- Drop 'Spec' suffix from all turbomind model classes and files
  (TextModelSpec → TextModel, Qwen3TextSpec → Qwen3TextModel, etc.)
- Extract TextModelBuilder from _base.py into builders/text_model.py
- Move model-specific qk_norm from TextModel to Qwen3 and Qwen3.5
- Fix .gitignore typo (trubomind → turbomind)

…anup

Align all turbomind source models with Qwen3 conventions:
- Drop engine_cfg from model signatures, wire data_type via Context
- Add Context, ParallelGroup, make_moe_config, make_mla_config helpers
- Collapse make_*_config functions by removing per-function data_type
- Remove dead fields from C++ configs (has_bias, hidden_dim, etc.)
- Remove _layer_pattern, _embed_key, _norm_key from all models
- Unify FFN padding with group-based pad/round_up helpers
- Add TP padding for block-quantized formats and GEMM K-alignment
- Remove dead code: _pad_1d, _norm, pad_in_dim, _softmax_scale
- Add InternVL3.5, InternLM2/3, Llama turbomind support
- Rename fused_moe to is_expert, align Python/C++ config fields
- Use direct HF config access, Transformers type hints, all-params loader
- Clean up imports, docstrings, formatting across all model files

- Resolve conflicts by keeping our refactored architecture
- Thread trust_remote_code through from_pretrained → __init__ → _from_hf
  → is_supported → get_tm_config → get_model_arch
- Add is_cublas_grouped check to _should_fuse_silu: disable fused SiLU
  for bf16 MoE on SM100+ GPUs (CublasGroupedKernel limitation)