- index: unscheduled sources no longer link to /source (was 404); show 未排程 badge
- index: sources with toggle ON sort first
- logins page: split into per-source login-state table (site-shared instance
  column, per-source test via new /login-test-src route) + site-credential table
- platform_layer: skill_sources() exposes method; login_sites() drops direct
  sources; new login_source_rows()