test(repos): add SQL integration tests for 17 untested repo files

Add 148 integration tests exercising actual SQL against PostgreSQL for
all previously untested repository files. Includes 6 new fixture helpers
in testhelpers_db.go and CI PostgreSQL service configuration.

Discovered and documented existing RecordPurchase SQL bug (ambiguous
column reference in ON CONFLICT clause).

server/channelserver/repo_goocoo_test.go

@@ -0,0 +1,152 @@
+package channelserver
+
+import (
+	"testing"
+
+	"github.com/jmoiron/sqlx"
+)
+
+func setupGoocooRepo(t *testing.T) (*GoocooRepository, *sqlx.DB, uint32) {
+	t.Helper()
+	db := SetupTestDB(t)
+	userID := CreateTestUser(t, db, "goocoo_test_user")
+	charID := CreateTestCharacter(t, db, userID, "GoocooChar")
+	repo := NewGoocooRepository(db)
+	t.Cleanup(func() { TeardownTestDB(t, db) })
+	return repo, db, charID
+}
+
+func TestRepoGoocooEnsureExists(t *testing.T) {
+	repo, db, charID := setupGoocooRepo(t)
+
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("EnsureExists failed: %v", err)
+	}
+
+	var count int
+	if err := db.QueryRow("SELECT COUNT(*) FROM goocoo WHERE id=$1", charID).Scan(&count); err != nil {
+		t.Fatalf("Verification query failed: %v", err)
+	}
+	if count != 1 {
+		t.Errorf("Expected 1 goocoo row, got: %d", count)
+	}
+}
+
+func TestRepoGoocooEnsureExistsIdempotent(t *testing.T) {
+	repo, _, charID := setupGoocooRepo(t)
+
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("First EnsureExists failed: %v", err)
+	}
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("Second EnsureExists failed: %v", err)
+	}
+}
+
+func TestRepoGoocooSaveAndGetSlot(t *testing.T) {
+	repo, _, charID := setupGoocooRepo(t)
+
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("EnsureExists failed: %v", err)
+	}
+
+	data := []byte{0xAA, 0xBB, 0xCC}
+	if err := repo.SaveSlot(charID, 0, data); err != nil {
+		t.Fatalf("SaveSlot failed: %v", err)
+	}
+
+	got, err := repo.GetSlot(charID, 0)
+	if err != nil {
+		t.Fatalf("GetSlot failed: %v", err)
+	}
+	if len(got) != 3 || got[0] != 0xAA {
+		t.Errorf("Expected saved data, got: %x", got)
+	}
+}
+
+func TestRepoGoocooGetSlotNull(t *testing.T) {
+	repo, _, charID := setupGoocooRepo(t)
+
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("EnsureExists failed: %v", err)
+	}
+
+	got, err := repo.GetSlot(charID, 0)
+	if err != nil {
+		t.Fatalf("GetSlot failed: %v", err)
+	}
+	if got != nil {
+		t.Errorf("Expected nil for NULL slot, got: %x", got)
+	}
+}
+
+func TestRepoGoocooSaveMultipleSlots(t *testing.T) {
+	repo, _, charID := setupGoocooRepo(t)
+
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("EnsureExists failed: %v", err)
+	}
+
+	if err := repo.SaveSlot(charID, 0, []byte{0x01}); err != nil {
+		t.Fatalf("SaveSlot(0) failed: %v", err)
+	}
+	if err := repo.SaveSlot(charID, 3, []byte{0x04}); err != nil {
+		t.Fatalf("SaveSlot(3) failed: %v", err)
+	}
+
+	got0, _ := repo.GetSlot(charID, 0)
+	got3, _ := repo.GetSlot(charID, 3)
+	if len(got0) != 1 || got0[0] != 0x01 {
+		t.Errorf("Slot 0 unexpected: %x", got0)
+	}
+	if len(got3) != 1 || got3[0] != 0x04 {
+		t.Errorf("Slot 3 unexpected: %x", got3)
+	}
+}
+
+func TestRepoGoococClearSlot(t *testing.T) {
+	repo, _, charID := setupGoocooRepo(t)
+
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("EnsureExists failed: %v", err)
+	}
+
+	if err := repo.SaveSlot(charID, 2, []byte{0xFF}); err != nil {
+		t.Fatalf("SaveSlot failed: %v", err)
+	}
+
+	if err := repo.ClearSlot(charID, 2); err != nil {
+		t.Fatalf("ClearSlot failed: %v", err)
+	}
+
+	got, err := repo.GetSlot(charID, 2)
+	if err != nil {
+		t.Fatalf("GetSlot failed: %v", err)
+	}
+	if got != nil {
+		t.Errorf("Expected nil after ClearSlot, got: %x", got)
+	}
+}
+
+func TestRepoGoocooInvalidSlot(t *testing.T) {
+	repo, _, charID := setupGoocooRepo(t)
+
+	if err := repo.EnsureExists(charID); err != nil {
+		t.Fatalf("EnsureExists failed: %v", err)
+	}
+
+	_, err := repo.GetSlot(charID, 5)
+	if err == nil {
+		t.Fatal("Expected error for invalid slot index 5")
+	}
+
+	err = repo.SaveSlot(charID, 5, []byte{0x00})
+	if err == nil {
+		t.Fatal("Expected error for SaveSlot with invalid slot index 5")
+	}
+
+	err = repo.ClearSlot(charID, 5)
+	if err == nil {
+		t.Fatal("Expected error for ClearSlot with invalid slot index 5")
+	}
+}