model: Add support for Nanbeige4.2 (#25994)

* support nanbeige4.2 model

* fix

* fix flake8 Lint check

* fix loop bound check and drop redundant head_dim

---------

Co-authored-by: root <lizongqiang@kanzhun.com>

src/llama-arch.cpp

@@ -143,6 +143,7 @@ static const std::map<llm_arch, const char *> LLM_ARCH_NAMES = {
     { LLM_ARCH_KIMI_LINEAR,      "kimi-linear"      },
     { LLM_ARCH_TALKIE,           "talkie"           },
     { LLM_ARCH_MELLUM,           "mellum"           },
+    { LLM_ARCH_NANBEIGE,         "nanbeige"         },
     { LLM_ARCH_UNKNOWN,          "(unknown)"        },
 };
 
@@ -221,6 +222,8 @@ static const std::map<llm_kv, const char *> LLM_KV_NAMES = {
     { LLM_KV_TOKEN_SHIFT_COUNT,                 "%s.token_shift_count"                 },
     { LLM_KV_INTERLEAVE_MOE_LAYER_STEP,         "%s.interleave_moe_layer_step"         },
     { LLM_KV_FULL_ATTENTION_INTERVAL,           "%s.full_attention_interval"           },
+    { LLM_KV_NUM_LOOPS,                         "%s.num_loops"                         },
+    { LLM_KV_SKIP_LOOP_FINAL_NORM,              "%s.skip_loop_final_norm"              },
 
     { LLM_KV_ATTENTION_HEAD_COUNT,                   "%s.attention.head_count"                   },
     { LLM_KV_ATTENTION_HEAD_COUNT_KV,                "%s.attention.head_count_kv"                },