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_session_test.go

@@ -0,0 +1,141 @@
+package channelserver
+
+import (
+	"testing"
+
+	"github.com/jmoiron/sqlx"
+)
+
+func setupSessionRepo(t *testing.T) (*SessionRepository, *sqlx.DB, uint32, uint32, uint32, string) {
+	t.Helper()
+	db := SetupTestDB(t)
+	userID := CreateTestUser(t, db, "session_test_user")
+	charID := CreateTestCharacter(t, db, userID, "SessionChar")
+	token := "test_token_12345"
+	sessionID := CreateTestSignSession(t, db, userID, token)
+	repo := NewSessionRepository(db)
+	t.Cleanup(func() { TeardownTestDB(t, db) })
+	return repo, db, userID, charID, sessionID, token
+}
+
+func TestRepoSessionValidateLoginToken(t *testing.T) {
+	repo, _, _, charID, sessionID, token := setupSessionRepo(t)
+
+	err := repo.ValidateLoginToken(token, sessionID, charID)
+	if err != nil {
+		t.Fatalf("ValidateLoginToken failed: %v", err)
+	}
+}
+
+func TestRepoSessionValidateLoginTokenInvalidToken(t *testing.T) {
+	repo, _, _, charID, sessionID, _ := setupSessionRepo(t)
+
+	err := repo.ValidateLoginToken("wrong_token", sessionID, charID)
+	if err == nil {
+		t.Fatal("Expected error for invalid token, got nil")
+	}
+}
+
+func TestRepoSessionValidateLoginTokenWrongChar(t *testing.T) {
+	repo, _, _, _, sessionID, token := setupSessionRepo(t)
+
+	err := repo.ValidateLoginToken(token, sessionID, 999999)
+	if err == nil {
+		t.Fatal("Expected error for wrong char ID, got nil")
+	}
+}
+
+func TestRepoSessionValidateLoginTokenWrongSession(t *testing.T) {
+	repo, _, _, charID, _, token := setupSessionRepo(t)
+
+	err := repo.ValidateLoginToken(token, 999999, charID)
+	if err == nil {
+		t.Fatal("Expected error for wrong session ID, got nil")
+	}
+}
+
+func TestRepoSessionBindSession(t *testing.T) {
+	repo, db, _, charID, _, token := setupSessionRepo(t)
+
+	CreateTestServer(t, db, 1)
+
+	if err := repo.BindSession(token, 1, charID); err != nil {
+		t.Fatalf("BindSession failed: %v", err)
+	}
+
+	var serverID *uint16
+	var boundCharID *uint32
+	if err := db.QueryRow("SELECT server_id, char_id FROM sign_sessions WHERE token=$1", token).Scan(&serverID, &boundCharID); err != nil {
+		t.Fatalf("Verification query failed: %v", err)
+	}
+	if serverID == nil || *serverID != 1 {
+		t.Errorf("Expected server_id=1, got: %v", serverID)
+	}
+	if boundCharID == nil || *boundCharID != charID {
+		t.Errorf("Expected char_id=%d, got: %v", charID, boundCharID)
+	}
+}
+
+func TestRepoSessionClearSession(t *testing.T) {
+	repo, db, _, charID, _, token := setupSessionRepo(t)
+
+	CreateTestServer(t, db, 1)
+
+	if err := repo.BindSession(token, 1, charID); err != nil {
+		t.Fatalf("BindSession failed: %v", err)
+	}
+
+	if err := repo.ClearSession(token); err != nil {
+		t.Fatalf("ClearSession failed: %v", err)
+	}
+
+	var serverID, boundCharID *int
+	if err := db.QueryRow("SELECT server_id, char_id FROM sign_sessions WHERE token=$1", token).Scan(&serverID, &boundCharID); err != nil {
+		t.Fatalf("Verification query failed: %v", err)
+	}
+	if serverID != nil {
+		t.Errorf("Expected server_id=NULL, got: %v", *serverID)
+	}
+	if boundCharID != nil {
+		t.Errorf("Expected char_id=NULL, got: %v", *boundCharID)
+	}
+}
+
+func TestRepoSessionUpdatePlayerCount(t *testing.T) {
+	repo, db, _, _, _, _ := setupSessionRepo(t)
+
+	CreateTestServer(t, db, 1)
+
+	if err := repo.UpdatePlayerCount(1, 42); err != nil {
+		t.Fatalf("UpdatePlayerCount failed: %v", err)
+	}
+
+	var count int
+	if err := db.QueryRow("SELECT current_players FROM servers WHERE server_id=1").Scan(&count); err != nil {
+		t.Fatalf("Verification query failed: %v", err)
+	}
+	if count != 42 {
+		t.Errorf("Expected current_players=42, got: %d", count)
+	}
+}
+
+func TestRepoSessionUpdatePlayerCountTwice(t *testing.T) {
+	repo, db, _, _, _, _ := setupSessionRepo(t)
+
+	CreateTestServer(t, db, 1)
+
+	if err := repo.UpdatePlayerCount(1, 10); err != nil {
+		t.Fatalf("First UpdatePlayerCount failed: %v", err)
+	}
+	if err := repo.UpdatePlayerCount(1, 25); err != nil {
+		t.Fatalf("Second UpdatePlayerCount failed: %v", err)
+	}
+
+	var count int
+	if err := db.QueryRow("SELECT current_players FROM servers WHERE server_id=1").Scan(&count); err != nil {
+		t.Fatalf("Verification query failed: %v", err)
+	}
+	if count != 25 {
+		t.Errorf("Expected current_players=25, got: %d", count)
+	}
+}