Adv 2.0 L4d: pets dual-write pet_* off AdvCharacter to player_meta

Eight pet_* columns added to player_meta (flags packed into pet_flags_json).
PetState + load/upsert/backfill helpers; dual-writes wired at every pet
mutation site (arrival, naming, supply-shop unlock, babysit trickle,
morning defense, misty reactivation). Backfill idempotent, runs on Init.

L4 grep-empty exit criterion intentionally NOT met for adventure_pets.go:
helpers still take *AdventureCharacter because external callers (babysit,
scheduler, npcs, combat_bridge, combat_stats, dnd_sheet, arena, character)
read pet fields directly. Cross-file signature flip belongs after the
dual-write soak.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/plugin/adventure_scheduler.go

@@ -95,6 +95,7 @@ func (p *AdventurePlugin) sendMorningDMs() {
 			if err := saveAdvCharacter(&char); err != nil {
 				slog.Error("babysit: failed to save after daily trickle", "user", char.UserID, "err", err)
 			}
+			_ = upsertPlayerMetaPetState(char.UserID, petStateFromAdvChar(&char))
 			continue
 		}
 
@@ -124,6 +125,7 @@ func (p *AdventurePlugin) sendMorningDMs() {
 		if petEvent != "" {
 			char.PetMorningDefense = true
 			_ = saveAdvCharacter(&char)
+			_ = upsertPlayerMetaPetState(char.UserID, petStateFromAdvChar(&char))
 		}
 
 		// Send morning DM with choices