Add diffusion workload division to governance page

Document diffusion area ownership for runtime, optimization, and docs
based on maintainer team alignment. Update committer area descriptions
for @RuixiangMa, @wtomin, @ZJY0516, and @yuanheng-zhao.

Signed-off-by: hsliuustc0106 <liuhongsheng4@huawei.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

docs/community/governance.md

@@ -39,13 +39,34 @@ Committers have write access and merge rights. They typically have deep expertis
 - [@linyueqian](https://github.com/linyueqian): TTS and Omni Support
 - [@lishunyang12](https://github.com/lishunyang12): Quantization and Configuration
 - [@princepride](https://github.com/princepride): Diffusion and Omni Support
-- [@RuixiangMa](https://github.com/RuixiangMa): Diffusion
+- [@RuixiangMa](https://github.com/RuixiangMa): Diffusion models, parallel, cache, and docs
 - [@SamitHuang](https://github.com/SamitHuang): RL and Diffusion
 - [@tzhouam](https://github.com/tzhouam): Engine and New Model Support
-- [@wtomin](https://github.com/wtomin): Diffusion and Parallelism
+- [@wtomin](https://github.com/wtomin): Diffusion models, parallel, and docs
 - [@ZeldaHuang](https://github.com/ZeldaHuang): Omni Support
-- [@ZJY0516](https://github.com/ZJY0516): Diffusion and CustomOp
-- [@yuanheng-zhao](https://github.com/yuanheng-zhao): Diffusion and Omni Support
+- [@ZJY0516](https://github.com/ZJY0516): Diffusion attention backend, kernel fusion, and CustomOp
+- [@yuanheng-zhao](https://github.com/yuanheng-zhao): Diffusion cache, offload, and Omni Support
+
+## Diffusion Workload Division
+
+This section breaks down diffusion-related responsibilities. If you have PRs touching these areas, please ping the listed owners for review.
+
+### Runtime-related
+
+- Diffusion models: @RuixiangMa, @wtomin
+
+### Optimization
+
+- Parallel: @RuixiangMa, @wtomin
+- Attention backend: @ZJY0516
+- Cache: @yuanheng-zhao, @RuixiangMa, yongxiang
+- Offload: @yuanheng-zhao
+- Quantization: @lishunyang12, @david6666666
+- Kernel fusion / communication-computation: @ZJY0516
+
+### Docs & Test
+
+- Diffusion docs: @RuixiangMa, @wtomin
 
 ## Meetings