model: support GLM 4.5 family of models (#14939)

* model: Add GLM 4.5 (#14921)

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

* Merge in PR suggestions

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

* model: Add GLM 4.5 family of models (#14921)

1. Updated tensor_mapping.py with NextN tensor mappings

- Added proper tensor mappings for all NextN/MTP tensors in /Users/samm/git/llama.cpp/gguf-py/gguf/tensor_mapping.py
- Added mappings for: eh_proj, embed_tokens, enorm, hnorm, shared_head.head, shared_head.norm

2. Added num_nextn_predict_layers configuration

- Added LLM_KV_NUM_NEXTN_PREDICT_LAYERS constant to llama-arch.h and llama-arch.cpp
- Added num_nextn_predict_layers field to llama_hparams struct
- Updated GLM4_MOE parameter loading in llama-model.cpp to read this parameter
- Modified tensor loading logic to conditionally load NextN tensors based on num_nextn_predict_layers
- Added GGUF writer support in gguf_writer.py with add_num_nextn_predict_layers() method
- Updated conversion script to extract and write this parameter from HuggingFace config

3. Added FIM tokens for GLM4_MOE

- Added GLM-4.5's FIM tokens to llama-vocab.cpp:
  - <|code_prefix|> for FIM_PRE
  - <|code_suffix|> for FIM_SUF
  - <|code_middle|> for FIM_MID

4. Removed manual NextN tensor handling

- Removed the special-case handling in convert_hf_to_gguf.py that manually mapped NextN tensors
- NextN tensors are now handled automatically through the proper tensor mapping system

* glm 4.5 update tensors names

* model: glm 4.5 apply suggestions from code review

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

* Update src/llama-model.cpp

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

* model: glm 4.5 apply suggestions from code review

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

* model: glm 4.5 apply suggestions from code review

* Apply suggestions from code review

* patch broken chat template

* typings fix

* add TENSOR_SKIP flag


Co-authored-by: Diego Devesa <slarengh@gmail.com>

* Update src/llama-model-loader.h

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

---------

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>
Co-authored-by: Diego Devesa <slarengh@gmail.com>

src/llama-arch.h

@@ -66,6 +66,7 @@ enum llm_arch {
     LLM_ARCH_DEEPSEEK2,
     LLM_ARCH_CHATGLM,
     LLM_ARCH_GLM4,
+    LLM_ARCH_GLM4_MOE,
     LLM_ARCH_BITNET,
     LLM_ARCH_T5,
     LLM_ARCH_T5ENCODER,
@@ -131,6 +132,7 @@ enum llm_kv {
     LLM_KV_EXPERT_WEIGHTS_NORM,
     LLM_KV_EXPERT_GATING_FUNC,
     LLM_KV_MOE_EVERY_N_LAYERS,
+    LLM_KV_NEXTN_PREDICT_LAYERS,
     LLM_KV_POOLING_TYPE,
     LLM_KV_LOGIT_SCALE,
     LLM_KV_DECODER_START_TOKEN_ID,
@@ -409,6 +411,12 @@ enum llm_tensor {
     LLM_TENSOR_SHORTCONV_CONV,
     LLM_TENSOR_SHORTCONV_INPROJ,
     LLM_TENSOR_SHORTCONV_OUTPROJ,
+    LLM_TENSOR_NEXTN_EH_PROJ,
+    LLM_TENSOR_NEXTN_EMBED_TOKENS,
+    LLM_TENSOR_NEXTN_ENORM,
+    LLM_TENSOR_NEXTN_HNORM,
+    LLM_TENSOR_NEXTN_SHARED_HEAD_HEAD,
+    LLM_TENSOR_NEXTN_SHARED_HEAD_NORM,
 };
 
 enum llm_tensor_layer {