Admin-managed feedback categories

Categories move from a hard-coded list to a feedback_categories table
(migration 0062), seeded with the four existing keys, labels and
descriptions so production feedback is untouched; any other key already in
use gets an archived category. Keys are fixed, so renames relabel past
feedback. Archive hides a category from the form; only unused categories
can be deleted. Submissions are validated against active categories, and
feedback responses carry category_label.

New: GET /feedback/categories (public); /admin/feedback/categories CRUD +
reorder behind the new feedback:categories permission (granted to Admin).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/service/feedback_category_service.go

@@ -0,0 +1,124 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/prabhupadasays/spsays-bff/internal/model"
+	"github.com/prabhupadasays/spsays-bff/internal/repository"
+)
+
+const (
+	maxCategoryLabel       = 60
+	maxCategoryDescription = 200
+)
+
+var (
+	ErrCategoryLabel       = fmt.Errorf("a category needs a name (up to %d characters)", maxCategoryLabel)
+	ErrCategoryDescription = fmt.Errorf("the description can be up to %d characters", maxCategoryDescription)
+	ErrCategoryLastActive  = errors.New("the feedback form needs at least one category")
+)
+
+var categoryNonSlug = regexp.MustCompile(`[^a-z0-9]+`)
+
+// FeedbackCategoryService manages the /feedback form's categories.
+type FeedbackCategoryService struct {
+	repo *repository.FeedbackCategoryRepo
+}
+
+func NewFeedbackCategoryService(repo *repository.FeedbackCategoryRepo) *FeedbackCategoryService {
+	return &FeedbackCategoryService{repo: repo}
+}
+
+// Active is what the /feedback form offers, in order.
+func (s *FeedbackCategoryService) Active(ctx context.Context) ([]model.FeedbackCategory, error) {
+	return s.repo.List(ctx, false)
+}
+
+// All is the admin's view: archived ones too, with usage counts.
+func (s *FeedbackCategoryService) All(ctx context.Context) ([]model.FeedbackCategory, error) {
+	return s.repo.List(ctx, true)
+}
+
+func cleanCategory(label, description string) (string, string, error) {
+	label = strings.TrimSpace(label)
+	description = strings.TrimSpace(description)
+	if label == "" || len([]rune(label)) > maxCategoryLabel {
+		return "", "", ErrCategoryLabel
+	}
+	if len([]rune(description)) > maxCategoryDescription {
+		return "", "", ErrCategoryDescription
+	}
+	return label, description, nil
+}
+
+// Create adds a category to the end of the form. Its key is derived from
+// the name ("Audio problem" → audio_problem) and fixed from then on, so it
+// can be renamed freely later without touching past feedback.
+func (s *FeedbackCategoryService) Create(ctx context.Context, label, description string) (*model.FeedbackCategory, error) {
+	label, description, err := cleanCategory(label, description)
+	if err != nil {
+		return nil, err
+	}
+	base := strings.Trim(categoryNonSlug.ReplaceAllString(strings.ToLower(label), "_"), "_")
+	if base == "" {
+		base = "category"
+	}
+	if len(base) > 40 {
+		base = strings.TrimRight(base[:40], "_")
+	}
+	key := base
+	for i := 2; ; i++ {
+		taken, err := s.repo.KeyTaken(ctx, key)
+		if err != nil {
+			return nil, err
+		}
+		if !taken {
+			break
+		}
+		key = fmt.Sprintf("%s_%d", base, i)
+	}
+	return s.repo.Create(ctx, key, label, description)
+}
+
+// Update renames, rewords, archives or restores a category. The last active
+// category can't be archived — the form would have nothing to offer.
+func (s *FeedbackCategoryService) Update(ctx context.Context, key, label, description string, archived bool) error {
+	label, description, err := cleanCategory(label, description)
+	if err != nil {
+		return err
+	}
+	if archived {
+		if err := s.guardLastActive(ctx, key); err != nil {
+			return err
+		}
+	}
+	return s.repo.Update(ctx, key, label, description, archived)
+}
+
+// Delete removes a category nothing is filed under (otherwise: archive it).
+func (s *FeedbackCategoryService) Delete(ctx context.Context, key string) error {
+	if err := s.guardLastActive(ctx, key); err != nil {
+		return err
+	}
+	return s.repo.Delete(ctx, key)
+}
+
+// Reorder sets the form's order.
+func (s *FeedbackCategoryService) Reorder(ctx context.Context, keys []string) error {
+	return s.repo.Reorder(ctx, keys)
+}
+
+func (s *FeedbackCategoryService) guardLastActive(ctx context.Context, key string) error {
+	active, err := s.repo.List(ctx, false)
+	if err != nil {
+		return err
+	}
+	if len(active) == 1 && active[0].Key == key {
+		return ErrCategoryLastActive
+	}
+	return nil
+}