Bound QMoE workspace with configurable row tiling (#32097)
## Summary
Add optional row tiling to the CUDA grouped-QMoE path to bound temporary
workspace usage for larger inputs.
Tiling is disabled by default, preserving the existing execution path.
Applications can configure the maximum rows per tile for each ORT
session:
```json
"session_options": {
"ep.cuda.qmoe_row_tile_size": "64"
}
```
Each tile runs sequentially on the same CUDA stream and reuses its
routing metadata and runner workspace.
## Changes
- Add row-tile planning and bounded scratch-layout helpers.
- Reuse the grouped-MoE workspace across sequential row tiles.
- Add the `ep.cuda.qmoe_row_tile_size` session configuration entry.
- Keep `ORT_QMOE_ROW_TILE_SIZE` as a compatibility fallback.
- Add optional QMoE diagnostics for route, tile size, workspace size,
and tactic bucket.
## Qualification
- End-to-end generation produced identical token output with tiling
enabled.
- In the qualified large MoE workload, a 64-row tile reduced QMoE
temporary scratch from approximately 64 MB to 32 MB.
Row tiling remains opt-in.
