perf(tests): copy a migrated template DB instead of migrating per test

Most tests opened a throwaway panel DB with database.InitDB, which runs the
full AutoMigrate + seed on an empty file every time: ~230ms, and ~850ms under
-race because GORM's reflection-heavy migration is what the detector slows
most. internal/web/service does this in ~550 of its 830 tests, so the CI race
job spent ~10 of its ~14.6 minutes re-migrating empty databases.

internal/database/dbtest.InitDB migrates once per test process, then hands
each test its own copy of that file (~130ms under -race) and registers the
CloseDB cleanup. The copy then goes through InitDB like a panel restart, so
every test still starts from the state a fresh install has. Tests that reopen
an existing file, migrate a hand-built legacy DB or target Postgres keep
calling database.InitDB.

Locally under -race: internal/web/service 626s (last CI run) -> 114s,
internal/sub 246s -> 35s.

internal/web/service/tgbot/tgbot_add_client_picker_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/dbtest"
 	"github.com/mhsanaei/3x-ui/v3/internal/database/model"
 
 	"github.com/mymmrac/telego"
@@ -15,10 +16,7 @@ import (
 
 func seedPickerInbounds(t *testing.T, protocols ...model.Protocol) {
 	t.Helper()
-	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
-		t.Fatalf("InitDB: %v", err)
-	}
-	t.Cleanup(func() { _ = database.CloseDB() })
+	dbtest.InitDB(t, filepath.Join(t.TempDir(), "x-ui.db"))
 	for i, protocol := range protocols {
 		port := 20000 + i
 		ib := &model.Inbound{Remark: string(protocol), Enable: true, Port: port, Protocol: protocol, Tag: fmt.Sprintf("inbound-%d", port), Settings: `{}`}

internal/web/service/tgbot/tgbot_client_draft_per_admin_test.go

@@ -4,7 +4,7 @@ import (
 	"path/filepath"
 	"testing"
 
-	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/dbtest"
 
 	"github.com/mymmrac/telego"
 )
@@ -12,10 +12,7 @@ import (
 // Regression test: keying the add-client wizard by chat alone left the two
 // admins of a group chat filling in one client between them.
 func TestAddClientDraftIsPerAdminInGroupChat(t *testing.T) {
-	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
-		t.Fatalf("InitDB: %v", err)
-	}
-	t.Cleanup(func() { _ = database.CloseDB() })
+	dbtest.InitDB(t, filepath.Join(t.TempDir(), "x-ui.db"))
 
 	const (
 		groupChat = int64(-1001234567890)

internal/web/service/tgbot/tgbot_client_draft_per_chat_test.go

@@ -11,7 +11,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/dbtest"
 
 	"github.com/mymmrac/telego"
 )
@@ -84,10 +84,7 @@ func lastDraftCard(t *testing.T, texts []string) string {
 // Regression test: one package-level draft per bot meant an admin's new client
 // was filled in by another chat's steps.
 func TestAddClientDraftIsPerChat(t *testing.T) {
-	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
-		t.Fatalf("InitDB: %v", err)
-	}
-	t.Cleanup(func() { _ = database.CloseDB() })
+	dbtest.InitDB(t, filepath.Join(t.TempDir(), "x-ui.db"))
 
 	const (
 		chatA = int64(7101)

internal/web/service/tgbot/tgbot_client_expiry_test.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/dbtest"
 	"github.com/mhsanaei/3x-ui/v3/internal/web/locale"
 	"github.com/mhsanaei/3x-ui/v3/internal/xray"
 
@@ -35,10 +35,7 @@ func clientInfoLocalizer(t *testing.T) {
 // Regression test: a start-after-first-use client is stored as a negative duration,
 // and a disabled one rendered it as a 1969 date.
 func TestClientInfoShowsStartAfterFirstUseWhenDisabled(t *testing.T) {
-	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
-		t.Fatalf("InitDB: %v", err)
-	}
-	t.Cleanup(func() { _ = database.CloseDB() })
+	dbtest.InitDB(t, filepath.Join(t.TempDir(), "x-ui.db"))
 	clientInfoLocalizer(t)
 
 	traffic := &xray.ClientTraffic{

internal/web/service/tgbot/tgbot_client_links_authz_test.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/dbtest"
 	"github.com/mhsanaei/3x-ui/v3/internal/database/model"
 	"github.com/mhsanaei/3x-ui/v3/internal/web/global"
 	"github.com/mhsanaei/3x-ui/v3/internal/xray"
@@ -33,10 +34,7 @@ func newLinksCallbackTgbot(t *testing.T, email string) (*Tgbot, func(string) int
 	swapTestBot(t, mock.URL)
 	t.Cleanup(mock.Close)
 
-	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
-		t.Fatalf("InitDB: %v", err)
-	}
-	t.Cleanup(func() { _ = database.CloseDB() })
+	dbtest.InitDB(t, filepath.Join(t.TempDir(), "x-ui.db"))
 
 	inbound := &model.Inbound{
 		UserId:   1,

internal/web/service/tgbot/tgbot_report_batching_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 
 	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/dbtest"
 	"github.com/mhsanaei/3x-ui/v3/internal/database/model"
 	"github.com/mhsanaei/3x-ui/v3/internal/xray"
 
@@ -59,10 +60,7 @@ func seedReportClients(t *testing.T, remark string, emails []string) {
 
 func initReportDB(t *testing.T) *Tgbot {
 	t.Helper()
-	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
-		t.Fatalf("InitDB: %v", err)
-	}
-	t.Cleanup(func() { _ = database.CloseDB() })
+	dbtest.InitDB(t, filepath.Join(t.TempDir(), "x-ui.db"))
 
 	origRunning := isRunning
 	t.Cleanup(func() { isRunning = origRunning })

internal/web/service/tgbot/tgbot_stale_button_test.go

@@ -8,7 +8,7 @@ import (
 	"sync"
 	"testing"
 
-	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/dbtest"
 	"github.com/mhsanaei/3x-ui/v3/internal/database/model"
 
 	"github.com/mymmrac/telego"
@@ -58,10 +58,7 @@ func swapTestBot(t *testing.T, url string) {
 
 func newStaleButtonTgbot(t *testing.T) *Tgbot {
 	t.Helper()
-	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
-		t.Fatalf("InitDB: %v", err)
-	}
-	t.Cleanup(func() { _ = database.CloseDB() })
+	dbtest.InitDB(t, filepath.Join(t.TempDir(), "x-ui.db"))
 	return &Tgbot{}
 }