model : add HunyuanOCR support (#21395)

* HunyuanOCR: add support for text and vision models

- Add HunyuanOCR vision projector (perceiver-based) with Conv2d merge
- Add separate HUNYUAN_OCR chat template (content-before-role format)
- Handle HunyuanOCR's invalid pad_token_id=-1 in converter
- Fix EOS/EOT token IDs from generation_config.json
- Support xdrope RoPE scaling type
- Add tensor mappings for perceiver projector (mm.before_rms, mm.after_rms, etc.)
- Register HunYuanVLForConditionalGeneration for both text and mmproj conversion

* fix proper mapping

* Update gguf-py/gguf/tensor_mapping.py

Co-authored-by: Xuan-Son Nguyen <thichthat@gmail.com>

* Update tools/mtmd/clip.cpp

Co-authored-by: Xuan-Son Nguyen <thichthat@gmail.com>

* address comments

* update

* Fix typecheck

* Update convert_hf_to_gguf.py

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

* Update convert_hf_to_gguf.py

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

* Update convert_hf_to_gguf.py

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

* Update convert_hf_to_gguf.py

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

---------

Co-authored-by: Xuan-Son Nguyen <thichthat@gmail.com>
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

tools/mtmd/clip-impl.h

@@ -148,6 +148,11 @@
 #define TN_TOK_BOI         "v.boi"
 #define TN_TOK_EOI         "v.eoi"
 
+// hunyuanocr
+#define TN_MM_PRE_NORM     "mm.pre_norm.%s"
+#define TN_TOK_IMG_BEGIN   "mm.image_begin"
+#define TN_TOK_IMG_END     "mm.image_end"
+
 // deepseek-ocr
 #define TN_SAM_POS_EMBD   "v.sam.pos_embd.%s"
 #define TN_SAM_PATCH_EMBD "v.sam.patch_embd.%s"
@@ -266,6 +271,7 @@ enum projector_type {
     PROJECTOR_TYPE_YOUTUVL,
     PROJECTOR_TYPE_KIMIK25,
     PROJECTOR_TYPE_NEMOTRON_V2_VL,
+    PROJECTOR_TYPE_HUNYUANOCR,
     PROJECTOR_TYPE_UNKNOWN,
 };
 
@@ -306,6 +312,7 @@ static std::map<projector_type, std::string> PROJECTOR_TYPE_NAMES = {
     { PROJECTOR_TYPE_YOUTUVL,   "youtuvl"},
     { PROJECTOR_TYPE_KIMIK25,   "kimik25"},
     { PROJECTOR_TYPE_NEMOTRON_V2_VL, "nemotron_v2_vl"},
+    { PROJECTOR_TYPE_HUNYUANOCR, "hunyuanocr"},
 };
 
 static projector_type clip_projector_type_from_string(const std::string & str) {