Clean up loading code

- Centralized instantiation of the PEFT wrapper in `make_policy` for inference
  (e.g. in `lerobot-record`)
- Training a PEFT policy also sets `cfg.use_peft` so that all inference code loading
  the policy can rely on that attribute to identify if PEFT loading is needed
- Modified RTC example to also include PEFT policies. Mostly because this is an example
  I'm currently exploring.

src/lerobot/scripts/lerobot_train.py

@@ -188,7 +188,7 @@ def wrap_policy_in_peft_model(cfg, policy):
     if peft_config_cli["init_type"] is not None:
         if peft_method_type == "LORA":
             peft_config_policy["init_lora_weights"] = peft_config_cli["init_type"]
-        elif peft_method_type == "BONE":
+        elif peft_method_type == "MISS":
             peft_config_policy["init_weights"] = peft_config_cli["init_type"]
         else:
             raise ValueError(
@@ -200,6 +200,10 @@ def wrap_policy_in_peft_model(cfg, policy):
         peft_config_cls(**peft_config_policy),
     )
 
+    # Make sure that the config is tagged as using PEFT so that the loading code can take the
+    # appropriate steps to use the adapter weights and the PEFT config instead of the full model weights.
+    policy.config.use_peft = True
+
     return policy