### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

LiteLLM's prompt-caching-aware routing (`optional_pre_call_checks: ["prompt_caching"]`) stores the `model_id → cacheable_prefix_hash` binding with a hardcoded 5-minute TTL. This was correct when Anthropic only offered the 5-minute ephemeral cache, but it is now incorrect for the 1-hour cache (`cache_control: {"type": "ephemeral", "ttl": "1h"}`) supported by Anthropic and Bedrock.

In a multi-deployment setup (e.g., the same Bedrock model across multiple AWS accounts/regions, or multiple Anthropic API keys), this means:

1. Request at `t=0` lands on deployment A with `cache_control: {"type": "ephemeral", "ttl": "1h"}`. The provider caches the prefix for 60 minutes. LiteLLM stores `prefix_hash → A` for 5 minutes. 2. Request at `t=6 min` with the same prefix arrives. LiteLLM's affinity entry has expired, so the router falls back to its normal strategy (e.g., least-busy) and may pick deployment B. 3. Deployment B has no cache for the prefix → **provider-side cache miss**, full input token cost, even though deployment A is still holding the cache wa…