[Router] Add bucket-aware policy domains and native cache indexing (#38108)

Signed-off-by: Vincent Gao <vincentbo@linux.alibaba.com>
Co-authored-by: inkcherry <mingzhi.liu@amd.com>
Co-authored-by: yangbodong22011 <13137470+yangbodong22011@users.noreply.github.com>

experimental/sgl-router/tests/proxy/main.rs

@@ -10,6 +10,7 @@
 
 mod common;
 
+mod bucket_routing;
 mod cache_aware_input_ids;
 mod chat_routing;
 mod external_indexer_routing;
@@ -18,6 +19,7 @@ mod graceful_shutdown;
 mod header_forwarding;
 mod pd_bootstrap_injection;
 mod pd_pool_isolation;
+mod radix_tree_routing;
 mod roundrobin_input_ids;
 mod shared_prefill_admission;
 mod sticky_input_ids;