feat: add Mano manifold optimizer (mano_adamw)

- implement Mano (v2) with axis-rotating tangent projection and manifold normalization, replacing Newton-Schulz iteration
- composite ManoAdamW reuses partition_optimizer_parameters and composite helpers
- register mano_adamw in OptimizerFactory, export Mano and ManoAdamW
- add --mano_momentum and --mano_nesterov CLI options in Optimizer group
- add mano_adamw hyperparameters branch in train.py
- document mano_adamw in params.md
- add tests for single-step projection, axis alternation, factory registration, closure, and resume

astrai/optim/__init__.py

@@ -7,6 +7,7 @@ from astrai.optim.composite import (
     composite_zero_grad,
     refresh_param_groups,
 )
+from astrai.optim.mano_adamw import Mano, ManoAdamW
 from astrai.optim.muon_adamw import MuonAdamW
 from astrai.optim.nora_nadamw import (
     NAdamW,
@@ -19,6 +20,8 @@ from astrai.optim.nora_nadamw import (
 )
 
 __all__ = [
+    "Mano",
+    "ManoAdamW",
     "MuonAdamW",
     "NAdamW",
     "Nora",