update --use-kv-events to --kv-events flag

docs/architecture/kv_cache_routing.md

@@ -21,7 +21,7 @@ The KV-aware routing arguments:
 
 - `--router-temperature`: Sets the temperature when randomly selecting workers to route to via softmax sampling on the router cost logits. Setting it to 0 recovers the deterministic behavior where the min logit is picked.
 
-- `--use-kv-events`: Sets whether to listen to KV events for maintaining the global view of cached blocks. If true, then we use the `KvIndexer` to listen to the block creation and deletion events. If false, `ApproxKvIndexer`, which assumes the kv cache of historical prompts exists for fixed time durations (hard-coded to 120s), is used to predict the kv cache hit ratio in each engine. Set false if your backend engine does not emit KV events.
+- `--kv-events`: Sets whether to listen to KV events for maintaining the global view of cached blocks. If true, then we use the `KvIndexer` to listen to the block creation and deletion events. If false, `ApproxKvIndexer`, which assumes the kv cache of historical prompts exists for fixed time durations (hard-coded to 120s), is used to predict the kv cache hit ratio in each engine. Set false if your backend engine does not emit KV events.
 
 
 ## Architecture