resolve_sidecar_dir() probes the filesystem (touch/unlink) and can mirror
sidecar files to HERMES_HOME. Doing that as a module-import side effect
meant plugin discovery, `hermes --help`, and test collection all paid a
filesystem probe (and possibly a mirror copy) just for importing the
photon adapter or CLI.
Convert _SIDECAR_DIR/_NPM_ERROR_LOG in adapter.py and cli.py to lazy
cached accessors (_sidecar_dir()/_npm_error_log()); resolution now
happens on first actual use. Existing tests that monkeypatch the
_SIDECAR_DIR module global keep working — the accessors honor a
non-None value. Adds a regression test proving import performs no
resolution.
b62fc24dfa