There should be a reasonable bound on document deletion after expiry has occurred

Today, there is no firm bound on when deletion happens after document expiry occurs. In the worst case, deletion may never happen at all under full eviction and a read-only workload. Since deletion after expiry happens under document access, this policy works well for KV. However, indexes such as GSI covered indexes, FTS and Views can continue to include expired-but-not-deleted items for an unbounded length of time.

Since we shouldn't have all indexes separately manage expiry and since expiry time (in the way it's currently defined) can only be computed on the node on which the document is stored it seems to make most sense for this to be a KV responsibility.