Memory leaks and fragmentation

Hard per-bucket caps across rings, pools and arenas, not just GOP/frame resets, keep streamerOS under 152 MB

A dev.to teardown publishes a seven-bucket memory budget for a Rust streaming stack, summing to 146 to 148 MB. The design logic is checkable line by line, but the 12-hour heap curve that would confirm it is not in the post.