fix: add types to all config properties

ref: N25B-380

src/control_backend/core/config.py

@@ -84,7 +84,7 @@ class BehaviourSettings(BaseModel):
     transcription_token_buffer: int = 10
 
     # Text belief extractor settings
-    conversation_history_length_limit = 10
+    conversation_history_length_limit: int = 10
 
 
 class LLMSettings(BaseModel):
@@ -101,8 +101,8 @@ class LLMSettings(BaseModel):
 
     local_llm_url: str = "http://localhost:1234/v1/chat/completions"
     local_llm_model: str = "gpt-oss"
-    chat_temperature = 1.0
-    code_temperature = 0.3
+    chat_temperature: float = 1.0
+    code_temperature: float = 0.3
     n_parallel: int = 4