feat: expand growth, equipment, and mail

- add character promotion and costume potential flows
- add equipment management and enhancement
- harden development mail and save tools

go/internal/gacha/gacha.go

@@ -47,6 +47,13 @@ func (s *Service) AttachEquipmentGacha(catalog *gamedata.EquipmentGachaCatalog,
 	s.equipmentCatalog, s.equipmentInventory = catalog, inventory
 }
 
+// FirstGachaCompleted reflects UserDBInfo.IsFirstGacha. The official symbol
+// map names the client-side property IsDoneFirstGachaPick, and the client sets
+// it after a GachaSubType=3 purchase succeeds.
+func (s *Service) FirstGachaCompleted() bool {
+	return s.collection.FirstGachaCompleted()
+}
+
 // BeginSession is called by the transport session after each successful
 // login. Request sequence numbers restart with the client, so the login ID is
 // part of the durable idempotency key: retries in one login remain idempotent,
@@ -408,7 +415,7 @@ func (s *Service) buyEquipment(seq, buyType uint64, tickets []player.Item, desig
 			if err != nil {
 				return 146, nil, true, err
 			}
-			entry := player.Equipment{ID: equipmentID, SortID: uint64(sort)}
+			entry := player.Equipment{ID: equipmentID, SortID: uint64(sort), Rank: []uint64{0, 0, 0}}
 			for _, o := range main {
 				entry.MainOption = append(entry.MainOption, player.EquipmentOption{GroupID: o.GroupID, ID: o.ID})
 			}

go/internal/gacha/gacha_test.go

@@ -74,6 +74,9 @@ func TestInfinitePreviewAndFreeConfirmationPersist(t *testing.T) {
 	if err != nil || !ok || code != 61 {
 		t.Fatalf("confirm code=%d ok=%v err=%v", code, ok, err)
 	}
+	if service.FirstGachaCompleted() {
+		t.Fatal("infinite product incorrectly completed the subtype-3 first pick")
+	}
 	reward, found, err := wire.Bytes(response, 1)
 	if err != nil || !found || countFields(reward, 2) != 1 || countFields(reward, 3) != 1 || countFields(reward, 9) != 9 || countFields(reward, 8) != 4 {
 		t.Fatalf("reward chars=%d costumes=%d upgrades=%d exchanges=%d found=%v err=%v", countFields(reward, 2), countFields(reward, 3), countFields(reward, 9), countFields(reward, 8), found, err)