Add **kwargs to model base class constructors (#9252)

Updated constructors for base and derived classes in chat, embedding,
rerank, sequence2txt, and tts models to accept **kwargs. This change
improves extensibility and allows passing additional parameters without
breaking existing interfaces.

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Co-authored-by: IT: Sop.Son <sop.son@feavn.local>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

rag/llm/embedding_model.py

@@ -37,7 +37,12 @@ from rag.utils import num_tokens_from_string, truncate
 
 
 class Base(ABC):
-    def __init__(self, key, model_name):
+    def __init__(self, key, model_name, **kwargs):
+        """
+        Constructor for abstract base class.
+        Parameters are accepted for interface consistency but are not stored.
+        Subclasses should implement their own initialization as needed.
+        """
         pass
 
     def encode(self, texts: list):
@@ -864,7 +869,7 @@ class VoyageEmbed(Base):
 class HuggingFaceEmbed(Base):
     _FACTORY_NAME = "HuggingFace"
 
-    def __init__(self, key, model_name, base_url=None):
+    def __init__(self, key, model_name, base_url=None, **kwargs):
         if not model_name:
             raise ValueError("Model name cannot be None")
         self.key = key
@@ -946,4 +951,4 @@ class Ai302Embed(Base):
     def __init__(self, key, model_name, base_url="https://api.302.ai/v1/embeddings"):
         if not base_url:
             base_url = "https://api.302.ai/v1/embeddings"
-        super().__init__(key, model_name, base_url)
+        super().__init__(key, model_name, base_url)