[FEATURE] Add support for VLA-Forget

[OnePunchMonk]

Is your feature request related to a problem?
A clear description of the problem.

Proposed Solution
Describe the solution you'd like.

Alternatives Considered
Any alternative solutions or features you've considered.

Use Case

# How would this feature be used?
unlearner = ErasusUnlearner(
    model=model,
    strategy="my_new_strategy",  # new capability
)

Additional Context
Any other context (papers, references, etc.)
Paper Reference: https://www.alphaxiv.org/abs/2604.03956