censor: mention that we check the heads in the help And add a message to will explain the possibly long time spent doing this.

persistent-nodemap: respect the mmap setting when refreshing data After writing updated data, we reload the in-memory data. However, that logic was… wrong. We were doing file read when mmap was requested and when the configuration was requesting to not use mmap… we were using it. This should now be fine.

rust-index: only access offsets if revlog is inline Accessing the `RwLock` ended up showing up in profiles even with no contention. Offsets only exist for inline revlogs, so gate everything behind an inline check.

rust-index: cache the head nodeids python list Same optimization as before, but for the nodeids this time.

rust-index: add fast-path for getting a list of all heads as nodes This avoids a lot of back-and-forth between Python and Rust. We forgo adding a fast-path in the `filteredchangelog` case yet. If it shows up in profiling, we might add the variant with a filter.

rust-index-cpython: cache the heads' PyList representation This is the same optimization that the C index does, we just have more separation of the Python and native sides.

rust-index: use a `BitVec` instead of plain `Vec` for heads computation The `Vec` method uses one byte per revision, this uses 1 per 8 revisions, which improves our memory footprint. For large graphs (10+ millions), this can make a measurable difference server-side. I have seen no measurable impact on execution speed.

rust-index: implement faster retain heads using a vec instead of a hashset This is the same optimization that the C index does, we're only catching up now because this showed up as slow in benchmarking.

rust-index: allow inlining VCSGraph parents across crates

rust-index: allow inlining `parents` across crates