backfillDnDCharactersFromAdv walks adventure_characters rows that have no
dnd_character row and inserts an auto-migrated character (race/class
inferred from archetypes, Level seeded from dndLevelFromCombatLevel).
Idempotent via LEFT JOIN — pending-setup drafts and existing rows are
skipped. Wired into Init after the L5f backfill.
With every legacy player guaranteed a D&D row, the soak-window fallbacks
in dndLevelForUser, rivalLevelForUser, and hospitalCostsForUser are
retired (they now floor at level 1). dndLevelFromCombatLevel itself
stays — still used by autoBuildCharacter and the !setup seed paths.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
