Register 8 more keys in the sysconfig registry (quota daily budget + backfill
reserve, recent-backfill window, shorts-probe params, enrich/autotag batch sizes)
and route their reads through the DB-override-or-env resolver at every call site
(quota.py, sync/runner.py, sync/videos.py, sync/autotag.py, sync/maintenance.py,
routes/scheduler.py). All read sites already had a db session in scope. Reads are
read-through (no cache), matching app.state; admin can tune them live, no redeploy.
Add a generic admin-editable config layer (epic 4a): system_config KV table
(migration 0021), a sysconfig registry that is the single source of truth for
DB-overridable keys (type/group/default/bounds/secret) + a DB-override-or-env
resolver, and admin endpoints (GET/PATCH/DELETE /api/admin/config + a test-email
probe). Secrets are Fernet-encrypted at rest (TOKEN_ENCRYPTION_KEY); without it
they stay env-only. First group wired end-to-end: Email/SMTP — email.py now
reads host/port/user/from/password via the resolver (own session, since email
is sent from background tasks).
