Follow-up to the salvaged #59076 commit:
- Replace the bare get_secret import with a module-level Slack-pattern
helper (_get_esecret): try get_secret, on UnscopedSecretError fall back
to os.getenv. The DEFAULT profile's email adapter constructs UNSCOPED
under multiplexing, where a bare get_secret raises and would crash the
email path on startup — the exact WhatsApp defect fixed in 5438e9c629
(whatsapp_common._get_wsecret).
- Extend scope coverage to the remaining scope-blind reads:
EMAIL_IMAP_PORT / EMAIL_SMTP_PORT / EMAIL_POLL_INTERVAL (_esecret_int
replacing utils.env_int) and EMAIL_TRUST_FROM_HEADER (_esecret_bool
replacing utils.env_bool).
- Add tests: default-profile unscoped-under-multiplex construction, and
scoped ports/trust-flag no-environ-inheritance.
ff89f1b862