JobTokenService.CreateTokenAsync queries cvSearch.JobProviders for any
enabled row; returns null (no token created) when the table is empty or
all providers are disabled. TriggerStartAsync snapshots enabled providers
from DB at session-start time, preserving the existing snapshot contract.
CvMatcherController guards link-building on a non-null TokenId so the
"Start a job search" CTA is omitted from match emails when no providers
are configured.
JobSearchSettings.Providers list removed — provider config now lives
exclusively in the DB. CvSearchJobTask.GetProviders falls back to an
empty list with a warning (snapshot should always be populated from DB).
Closes#35
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>