fix: return type

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "amrita_core"
-version = "0.4.3"
+version = "0.4.3.1"
 description = "Agent core of Project Amrita"
 readme = "README.md"
 requires-python = ">=3.10,<3.14"

src/amrita_core/chatmanager.py

@@ -24,7 +24,7 @@
 from .hook.matcher import MatcherManager
 from .libchat import call_completion, get_last_response, get_tokens, text_generator
 from .logging import debug_log, logger
-from .protocol import MessageContent, StringMessageContent
+from .protocol import MessageContent
 from .sessions import SessionsManager
 from .tokenizer import hybrid_token_count
 from .types import (
@@ -790,11 +790,9 @@ async def _process_chat(
         async for chunk in call_completion(
             send_messages, config=self.config, preset=self.preset
         ):
-            if isinstance(chunk, str):
-                await self.yield_response(StringMessageContent(chunk))
-            elif isinstance(chunk, UniResponse):
+            if isinstance(chunk, UniResponse):
                 response = chunk
-            elif isinstance(chunk, MessageContent):
+            elif isinstance(chunk, MessageContent | str):
                 await self.yield_response(chunk)
         if response is None:
             raise RuntimeError("No final response from chat adapter.")