feat(policies): Add FastWAM Policy (#3834)

* Add FastWAM policy

* Add FastWAM policy review updates

* big refactor to use models from diffusers and transformers

* changing reproducable results

* preparing for training adding some temporary debug code aswell to visualize model output

* re-parenting of some layers to enable proper zero-3 FSDP

* linting

* small fix for the preprocessor and padded images

* removing some preprocessors

* removing temporary debug code

* cleaning up

* updating uv lock after rebasing

* adding lazy imports

* linting

* fixing stale assertion

* make tokenizer/text-encoder model ids configurable + some nits

* moving and renaming files to have a cleaner file tree

* removed asserts from the model, added guard instead and completely removed useless asserts

* cleaning up imports

* removing is_main_process and custom logging logic

* removing unused / stale attention path, removing some of the stale forwards within wan/models

---------

Co-authored-by: ZibinDong <zibindong@outlook.com>
Co-authored-by: Steven Palma <imstevenpmwork@ieee.org>

pyproject.toml

@@ -229,6 +229,10 @@ robometer = ["lerobot[transformers-dep]", "lerobot[qwen-vl-utils-dep]", "lerobot
 topreward = ["lerobot[transformers-dep]"]
 xvla = ["lerobot[transformers-dep]"]
 eo1 = ["lerobot[transformers-dep]", "lerobot[qwen-vl-utils-dep]"]
+fastwam = [
+    "lerobot[transformers-dep]",
+    "lerobot[diffusers-dep]",
+]
 hilserl = ["lerobot[transformers-dep]", "lerobot[dataset]", "gym-hil>=0.1.14,<0.2.0", "lerobot[grpcio-dep]", "lerobot[placo-dep]"]
 vla_jepa = ["lerobot[transformers-dep]", "lerobot[diffusers-dep]", "lerobot[qwen-vl-utils-dep]"]
 
@@ -308,6 +312,7 @@ all = [
     "lerobot[pi]",
     "lerobot[molmoact2]",
     "lerobot[smolvla]",
+    "lerobot[fastwam]",
     # "lerobot[groot]", TODO(Steven): Gr00t requires specific installation instructions for flash-attn
     "lerobot[xvla]",
     "lerobot[hilserl]",
@@ -444,7 +449,8 @@ default.extend-ignore-identifiers-re = [
     "is_compileable",
     "ROBOTIS",
     "OT_VALUE",
-    "VanderBilt"
+    "VanderBilt",
+    "seperated_timestep",
 ]
 
 # TODO: Uncomment when ready to use