[Diffusion][Bug-Fix]: Fix Ulysses SP Accurary Error (#377)

Signed-off-by: Didan Deng <33117903+wtomin@users.noreply.github.com>
Signed-off-by: zjy0516 <riverclouds.zhu@qq.com>
Co-authored-by: Jiangyun Zhu <riverclouds.zhu@qq.com>

vllm_omni/diffusion/attention/parallel/__init__.py

@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+"""Parallel attention strategies.
+
+This package provides **communication / resharding strategies** for attention,
+orthogonal to the **attention kernel backend** (SDPA/Flash/Sage).
+
+The goal is to keep `vllm_omni.diffusion.attention.layer.Attention` small and
+extensible: adding a new parallelism method should not require editing the core
+Attention module, only adding a new strategy and selecting it in the factory.
+"""
+
+from .base import NoParallelAttention, ParallelAttentionContext, ParallelAttentionStrategy
+from .factory import build_parallel_attention_strategy
+
+__all__ = [
+    "ParallelAttentionStrategy",
+    "ParallelAttentionContext",
+    "NoParallelAttention",
+    "build_parallel_attention_strategy",
+]