refactor: привести кодовую базу в соответствие с канонами bible

- 400 → 422 для всех ошибок валидации входных данных (handlers: export, quote, sync, vendor_spec, partnumber_books, pricelist)
- SQL-запросы вынесены из handlers в localdb (partnumber_books, pricelist, support_bundle); ValidateMariaDBConnection перенесён в internal/db/validate.go
- List-ответы унифицированы: ключ items, поля total_count/page/per_page/total_pages (component, pricelist, partnumber_books); шаблоны обновлены
- Молчаливые ошибки заменены на slog.Warn/Error (support_bundle, vendor_spec, component, configuration, local_configuration, localdb)
- N+1 запросы устранены: batch-запросы в export.go и vendor_workspace_import.go
- fmt.Println → slog в cmd/ (qfs, migrate, migrate_ops_projects, migrate_project_updated_at)
- Заголовки recovery/verify добавлены во все 28 SQL-миграций
- Добавлены bible-local/runtime-flows.md и bible-local/decisions/
- Обновлён субмодуль bible до v0.2.0-13

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/handlers/setup.go

@@ -1,7 +1,6 @@
 package handlers
 
 import (
-	"errors"
 	"fmt"
 	"html/template"
 	"log/slog"
@@ -15,9 +14,6 @@ import (
 	"git.mchus.pro/mchus/quoteforge/internal/localdb"
 	"github.com/gin-gonic/gin"
 	mysqlDriver "github.com/go-sql-driver/mysql"
-	gormmysql "gorm.io/driver/mysql"
-	"gorm.io/gorm"
-	"gorm.io/gorm/logger"
 )
 
 type SetupHandler struct {
@@ -27,8 +23,6 @@ type SetupHandler struct {
 	restartSig chan struct{}
 }
 
-var errPermissionProbeRollback = errors.New("permission probe rollback")
-
 func NewSetupHandler(localDB *localdb.LocalDB, connMgr *db.ConnectionManager, _ string, restartSig chan struct{}) (*SetupHandler, error) {
 	funcMap := template.FuncMap{
 		"sub": func(a, b int) int { return a - b },
@@ -93,7 +87,7 @@ func (h *SetupHandler) TestConnection(c *gin.Context) {
 	}
 
 	dsn := buildMySQLDSN(host, port, database, user, password, 5*time.Second)
-	lotCount, canWrite, err := validateMariaDBConnection(dsn)
+	lotCount, canWrite, err := db.ValidateMariaDBConnection(dsn)
 	if err != nil {
 		_ = c.Error(err)
 		c.JSON(http.StatusOK, gin.H{
@@ -135,7 +129,7 @@ func (h *SetupHandler) SaveConnection(c *gin.Context) {
 
 	// Test connection first
 	dsn := buildMySQLDSN(host, port, database, user, password, 5*time.Second)
-	if _, _, err := validateMariaDBConnection(dsn); err != nil {
+	if _, _, err := db.ValidateMariaDBConnection(dsn); err != nil {
 		_ = c.Error(err)
 		c.JSON(http.StatusBadRequest, gin.H{
 			"success": false,
@@ -214,46 +208,3 @@ func buildMySQLDSN(host string, port int, database, user, password string, timeo
 	return cfg.FormatDSN()
 }
 
-func validateMariaDBConnection(dsn string) (int64, bool, error) {
-	db, err := gorm.Open(gormmysql.Open(dsn), &gorm.Config{
-		Logger: logger.Default.LogMode(logger.Silent),
-	})
-	if err != nil {
-		return 0, false, fmt.Errorf("open MariaDB connection: %w", err)
-	}
-
-	sqlDB, err := db.DB()
-	if err != nil {
-		return 0, false, fmt.Errorf("get database handle: %w", err)
-	}
-	defer sqlDB.Close()
-
-	if err := sqlDB.Ping(); err != nil {
-		return 0, false, fmt.Errorf("ping MariaDB: %w", err)
-	}
-
-	var lotCount int64
-	if err := db.Table("lot").Count(&lotCount).Error; err != nil {
-		return 0, false, fmt.Errorf("check required table lot: %w", err)
-	}
-
-	return lotCount, testSyncWritePermission(db), nil
-}
-
-func testSyncWritePermission(db *gorm.DB) bool {
-	sentinel := fmt.Sprintf("quoteforge-permission-check-%d", time.Now().UnixNano())
-	err := db.Transaction(func(tx *gorm.DB) error {
-		if err := tx.Exec(`
-			INSERT INTO qt_client_schema_state (username, hostname, last_checked_at, updated_at)
-			VALUES (?, ?, NOW(), NOW())
-			ON DUPLICATE KEY UPDATE
-				last_checked_at = VALUES(last_checked_at),
-				updated_at = VALUES(updated_at)
-		`, sentinel, "setup-check").Error; err != nil {
-			return err
-		}
-		return errPermissionProbeRollback
-	})
-
-	return errors.Is(err, errPermissionProbeRollback)
-}