feat(preferences): configurable photo info attributes stored in user profile

- backend: users.preferences jsonb (migration 000004), Me returns preferences, PATCH /auth/me/preferences with validation (visible list + labels)
- frontend: gear in info section opens PhotoInfoSettingsDialog; base attribute set shown by default, remaining under ellipsis; per-attribute visibility and custom labels persisted to the profile; reset clears settings from the profile
- frontend: dialog has select-all/deselect-all icon buttons (no 'show all'); EXIF constants extracted to lib/exif.ts
- fix: render modal overlays via portal to document.body so they center in the viewport despite transformed panel/rail ancestors
- openspec: sync lightroom-workspace-ui artifacts (spec/design/proposal/tasks 9.8)

backend/internal/auth/store.go

@@ -2,6 +2,7 @@ package auth
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 
 	"github.com/jackc/pgx/v5"
@@ -29,27 +30,45 @@ func (s *Store) CreateUser(ctx context.Context, u *models.User) error {
 
 func (s *Store) GetUserByEmail(ctx context.Context, email string) (*models.User, error) {
 	return s.scanUser(s.pool.QueryRow(ctx,
-		`SELECT id, email, password_hash, name, COALESCE(avatar_url, ''), created_at
+		`SELECT id, email, password_hash, name, COALESCE(avatar_url, ''),
+		        COALESCE(preferences, '{}'::jsonb)::text, created_at
 		 FROM users WHERE lower(email) = lower($1)`, email))
 }
 
 func (s *Store) GetUserByID(ctx context.Context, id string) (*models.User, error) {
 	return s.scanUser(s.pool.QueryRow(ctx,
-		`SELECT id, email, password_hash, name, COALESCE(avatar_url, ''), created_at
+		`SELECT id, email, password_hash, name, COALESCE(avatar_url, ''),
+		        COALESCE(preferences, '{}'::jsonb)::text, created_at
 		 FROM users WHERE id = $1`, id))
 }
 
 func (s *Store) scanUser(row pgx.Row) (*models.User, error) {
 	var u models.User
-	if err := row.Scan(&u.ID, &u.Email, &u.PasswordHash, &u.Name, &u.AvatarURL, &u.CreatedAt); err != nil {
+	var prefs string
+	if err := row.Scan(&u.ID, &u.Email, &u.PasswordHash, &u.Name, &u.AvatarURL, &prefs, &u.CreatedAt); err != nil {
 		if errors.Is(err, pgx.ErrNoRows) {
 			return nil, ErrNotFound
 		}
 		return nil, err
 	}
+	if prefs != "" && prefs != "null" {
+		_ = json.Unmarshal([]byte(prefs), &u.Preferences)
+	}
 	return &u, nil
 }
 
+func (s *Store) UpdatePreferences(ctx context.Context, userID string, raw []byte) error {
+	tag, err := s.pool.Exec(ctx,
+		`UPDATE users SET preferences = $2::jsonb WHERE id = $1`, userID, string(raw))
+	if err != nil {
+		return err
+	}
+	if tag.RowsAffected() == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
 func (s *Store) CreateRefreshToken(ctx context.Context, t *models.RefreshToken) error {
 	_, err := s.pool.Exec(ctx,
 		`INSERT INTO refresh_tokens (id, user_id, token_hash, expires_at)