Fixed context usage calculation

sia/config.py

@@ -81,6 +81,12 @@ class Config:
             default=float(os.getenv('SIA_TEMPERATURE', '0.7')),
             help='LLM temperature parameter (default: 0.7, env: SIA_TEMPERATURE)'
         )
+        parser.add_argument(
+            '--token-limit',
+            type=int,
+            default=os.getenv('SIA_TOKEN_LIMIT'),
+            help='Token limit for the LLM (env: SIA_TOKEN_LIMIT)'
+        )
         self.args = parser.parse_args()
     
     def _parse_bool_env(self, env_var: str, default: bool) -> bool:
@@ -145,4 +151,9 @@ class Config:
     @property
     def temperature(self) -> float:
         """LLM temperature parameter."""
-        return self.args.temperature
+        return self.args.temperature
+    
+    @property
+    def token_limit(self) -> int:
+        """Token limit for the LLM."""
+        return self.args.token_limit