A long-lived serve process keeps a deleted profile as the context home of threads
that outlive the delete. A bare `mkdir(parents=True)` right before an atomic write
brings `profiles/<name>/` back after `hermes profile delete` has written the
tombstone and removed the tree.
The writers in `utils` and the seven callers named in #112592 are guarded by the
preceding commits; this one applies the same `mkdir_under_hermes_home` idiom to the
other pre-write directory creations found by the same mechanical rule (auth,
personality, plugin catalog, skills sync, tool discovery cache, platform adapters,
memory plugins, local runtime supervisor, process identity, breadcrumbs). The two
sites that pass `mode=` keep their mkdir behind `assert_named_profile_home_live`.
The guard is a no-op unless the target has a provable `profiles/<name>` ancestor.
Salvaged from #112596 (30-file sweep) on top of #112594 / #112601; the overlapping
files were resolved to the already-landed versions.
