Config: Fix draft model migration and loading

The loader takes in the "draft" parameter, so map the config model
to that when creating kwargs for initial load.

Also map the old "draft" key to the new "draft_model" key.

Signed-off-by: kingbri <bdashore3@proton.me>

common/tabby_config.py

@@ -72,7 +72,7 @@ def _from_file(self, config_path: pathlib.Path):
 
                 if model_cfg.get("draft"):
                     legacy = True
-                    cfg["draft"] = model_cfg["draft"]
+                    cfg["draft_model"] = model_cfg["draft"]
 
                 if model_cfg.get("lora"):
                     legacy = True

main.py

@@ -69,7 +69,11 @@ async def entrypoint_async():
         model_path = model_path / model_name
 
         # TODO: remove model_dump()
-        await model.load_model(model_path.resolve(), **config.model.model_dump())
+        await model.load_model(
+            model_path.resolve(),
+            **config.model.model_dump(),
+            draft=config.draft_model.model_dump(),
+        )
 
         # Load loras after loading the model
         if config.lora.loras: