The plugin loader execs sibling modules before the package __init__, so a
module-level `from . import _read_mem0_json` in _setup.py failed against the
empty parent shell and the whole module silently dropped out — every later
`hermes memory setup mem0` died with "cannot import name 'post_setup'".
The test loads mem0 through the real discovery path from a cold sys.modules
and asserts the cached _setup module exposes post_setup (red on base).
Also maps the contributor email for #103078 credit.
Campaign tracker: https://github.com/NousResearch/hermes-agent/issues/104154
c8cbc07030