Add Mixture of Experts (MoE) example

Port of cuTile Python's MoE.py sample with two kernels:
- fused_moe_kernel: tiled matmul with gather/scatter for expert routing
- silu_and_mul_kernel: element-wise SiLU activation

The Julia fused_moe_kernel uses opt_level=0 as a workaround for a
tileiras optimizer crash caused by token loop-carries from gather ops.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: maleadt

examples/Project.toml

@@ -1,6 +1,7 @@
 [deps]
 CUDA = "052768ef-5323-5732-b1bb-66c8b64840ba"
 FFTW = "7a1cc6ca-52ef-59f5-83cd-3a7055c09341"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 cuTile = "0dea8319-8c4a-4662-a73d-20234d115b9a"
 
 [sources]