Initial snapshot: hand motion pipeline (Dyn-HaMR + dex-retargeting + SPIDER)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

model/flow_matching/helpers/__init__.py

@@ -0,0 +1,20 @@
+"""Flow matching helpers package — direct reuse from ShapeR."""
+
+from model.flow_matching.helpers.path import AffineProbPath, PathSample
+from model.flow_matching.helpers.scheduler import (
+    CondOTScheduler,
+    FluxTimeSampler,
+    TimeSampler,
+)
+from model.flow_matching.helpers.solver import ODESolver
+from model.flow_matching.helpers.model_wrapper import ModelWrapper
+
+__all__ = [
+    "AffineProbPath",
+    "PathSample",
+    "CondOTScheduler",
+    "FluxTimeSampler",
+    "TimeSampler",
+    "ODESolver",
+    "ModelWrapper",
+]