fix(mc): fix runtime issue when starting mc

mcontainer/cli.py

@@ -32,6 +32,7 @@ def main(ctx: typer.Context) -> None:
             driver=None,
             project=None,
             env=[],
+            volume=[],
             name=None,
             no_connect=False,
             no_mount=False,

mcontainer/models.py

@@ -55,4 +55,6 @@ class Config(BaseModel):
     sessions: Dict[str, dict] = Field(
         default_factory=dict
     )  # Store as dict to avoid serialization issues
-    defaults: Dict[str, str] = Field(default_factory=dict)
+    defaults: Dict[str, object] = Field(
+        default_factory=dict
+    )  # Can store strings, booleans, or other values