Class ov::pass::EliminateConvPaddingMaskGating

class EliminateConvPaddingMaskGating : public ov::pass::MatcherPass

Eliminates the conv padding mask gating subgraph introduced by transformers 5.0+.

Transformers 5.0 added apply_mask_to_padding_states which multiplies hidden_states by attention_mask before conv layers. First observed in the LFM2 model. In PagedAttention mode, sequences are packed contiguously without padding, so this gating is always an identity (mask is all-1s).

Matches the pattern: attention_mask -> Slice -> Unsqueeze -> [Convert] -> Multiply -> Add -> Multiply(H, mask_expr) and replaces the final Multiply with its hidden_states input directly.