nordisk-alloc 0.1.0

The ONE long-lived-server allocator policy for the nordisk constellation — installs mimalloc AND tells it to hand freed memory back to the OS (`purge_delay` 10 ms, `arena_purge_mult` 1) so a dropped transient stops being resident forever. REUSE (LAW #5): mimalloc `0.1` compiles the v3 C sources, and v3 raised `purge_delay` from 10 ms to 1000 ms — at which point RSS is not memory in use but the running MAXIMUM of every transient the process ever built. MEASURED: a 2 GB transient dropped at the shipped default returned 0 bytes; at 10 ms it returned all but 156 MB. Every fat nordisk binary (dwarves-server, nornir-server, korp-server, holger, gunnar-service) wants this, and until now exactly one of them had it.