feat(05-01): restructure fonoteka plugins into Winter directories

- Move models, classes, controllers, middleware, and updates into subpackages
- Add self-registering models/updates/classes registries so later plans add files
- Keep the genres route and shipped migration SQL unchanged

classes/registry.go

@@ -0,0 +1,21 @@
+package classes
+
+import "gorm.io/gorm"
+
+var hookRegistrars []func(*gorm.DB) error
+
+// RegisterHook appends a GORM-callback registrant so later plans add files
+// without editing plugin.go Boot.
+func RegisterHook(fn func(*gorm.DB) error) {
+	hookRegistrars = append(hookRegistrars, fn)
+}
+
+// RegisterHooks runs every registered hook against gdb.
+func RegisterHooks(gdb *gorm.DB) error {
+	for _, fn := range hookRegistrars {
+		if err := fn(gdb); err != nil {
+			return err
+		}
+	}
+	return nil
+}

classes/user_lookup.go

@@ -0,0 +1,51 @@
+package classes
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"git.golem15.com/golem15/fonoteka/plugins/golem15/user/models"
+	"git.golem15.com/golem15/summercms/backpack"
+	"git.golem15.com/golem15/summercms/bouncer"
+	"gorm.io/gorm"
+)
+
+var _ bouncer.UserProvider = GormUsers{}
+
+// GormUsers loads JWT principals from the users table.
+type GormUsers struct {
+	App *backpack.App
+}
+
+func (g GormUsers) FindByID(ctx context.Context, id uint) (*bouncer.Principal, error) {
+	if g.App == nil {
+		return nil, fmt.Errorf("golem15.user: app is nil")
+	}
+	gdb, ok := g.App.Lookup[*gorm.DB]()
+	if !ok || gdb == nil {
+		return nil, fmt.Errorf("golem15.user: gorm handle is missing")
+	}
+	var row models.User
+	err := gdb.WithContext(ctx).Where("id = ?", id).Take(&row).Error
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &bouncer.Principal{ID: row.ID, MustChangePassword: row.MustChangePassword}, nil
+}
+
+// JWTSecret reads golem15.user.jwt.secret and fails loudly when it is empty.
+func JWTSecret(app *backpack.App) (string, error) {
+	if app == nil || app.Config == nil {
+		return "", fmt.Errorf("golem15.user: jwt.secret is empty (set SUMMER_GOLEM15__USER__JWT__SECRET)")
+	}
+	secret := strings.TrimSpace(app.Config.String("golem15.user.jwt.secret"))
+	if secret == "" {
+		return "", fmt.Errorf("golem15.user: jwt.secret is empty (set SUMMER_GOLEM15__USER__JWT__SECRET)")
+	}
+	return secret, nil
+}