The CharacterItem idempotency check was looking up by the seed's own
literal id instead of the (characterId, itemDefinitionId) unique index
that CharacterItem actually enforces. If the demo character had already
looted a worn-short-sword naturally, re-running the seed would miss
that row and try to insert a colliding duplicate, breaking seeding
instead of being a safe no-op. Look up by the real domain key and reuse
whatever id is found when wiring up the CharacterEquipment row.
Adds the two starter monster definitions and their location-monster
mapping (weights 70/30) to the vertical-slice seed, following the
same findOneBy/update-or-insert pattern used for locations, plus an
upsert on (locationId, monsterId) for the mapping. Copies the source
artwork into the served images/monsters directory and extends the
seed spec harness to cover both idempotent inserts.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
