Feature: retire without reclaim

Threads with tight latency or timing requirements (e.g. soft real-time, audio, high fps GUI) can't afford to reclaim when retiring objects.

There are two ways this could be exposed on `HazPtrObject`:

1) `unsafe fn retire_no_reclaim(this: *mut Self, deleter: &'static dyn Deleter) -> usize`
2) `unsafe fn retire(this: *mut Self, allow_reclaim: bool, deleter: &'static dyn Deleter) -> usize`

I mildly prefer (2). I'm happy to send a PR or leave for discussion on the next stream.

Start by reading the HazPtrObject API and the existing retirement path, then compare the two proposed interfaces: a separate retire_no_reclaim method or an allow_reclaim parameter. The design must first settle which API to expose and ensure retirement can avoid reclamation for latency-sensitive threads.

Written by the indexing model from the issue text.