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/handlers.go

@@ -1,6 +1,9 @@
 package auth
 
 import (
+	"encoding/json"
+	"fmt"
+	"io"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
@@ -89,5 +92,79 @@ func (h *Handler) Me(c *gin.Context) {
 		httpx.RespondError(c, httpx.Unauthorized("unauthorized", "user not found"))
 		return
 	}
-	c.JSON(http.StatusOK, gin.H{"user": u.Public()})
+	prefs := u.Preferences
+	if prefs == nil {
+		prefs = map[string]any{}
+	}
+	c.JSON(http.StatusOK, gin.H{"user": u.Public(), "preferences": prefs})
+}
+
+const (
+	maxVisibleAttrs       = 500
+	maxLabelEntries       = 500
+	maxPreferenceKeyLen   = 128
+	maxPreferenceValueLen = 128
+)
+
+type photoInfoPreferences struct {
+	Visible []string          `json:"visible"`
+	Labels  map[string]string `json:"labels,omitempty"`
+}
+
+type preferencesPayload struct {
+	PhotoInfo *photoInfoPreferences `json:"photo_info,omitempty"`
+}
+
+func (p preferencesPayload) validate() error {
+	pi := p.PhotoInfo
+	if pi == nil {
+		return nil
+	}
+	if len(pi.Visible) > maxVisibleAttrs {
+		return fmt.Errorf("too many visible attributes")
+	}
+	for _, k := range pi.Visible {
+		if k == "" || len(k) > maxPreferenceKeyLen {
+			return fmt.Errorf("invalid visible attribute key")
+		}
+	}
+	if len(pi.Labels) > maxLabelEntries {
+		return fmt.Errorf("too many label overrides")
+	}
+	for k, v := range pi.Labels {
+		if k == "" || len(k) > maxPreferenceKeyLen {
+			return fmt.Errorf("invalid label key")
+		}
+		if len(v) > maxPreferenceValueLen {
+			return fmt.Errorf("label value too long")
+		}
+	}
+	return nil
+}
+
+func (h *Handler) UpdatePreferences(c *gin.Context) {
+	body, err := io.ReadAll(io.LimitReader(c.Request.Body, 1<<20))
+	if err != nil {
+		httpx.RespondError(c, httpx.BadRequest("invalid_preferences", "could not read request body"))
+		return
+	}
+	var payload preferencesPayload
+	if err := json.Unmarshal(body, &payload); err != nil {
+		httpx.RespondError(c, httpx.BadRequest("invalid_preferences", "preferences must be a JSON object"))
+		return
+	}
+	if err := payload.validate(); err != nil {
+		httpx.RespondError(c, httpx.BadRequest("invalid_preferences", err.Error()))
+		return
+	}
+	raw, err := json.Marshal(payload)
+	if err != nil {
+		httpx.RespondError(c, httpx.BadRequest("invalid_preferences", "could not encode preferences"))
+		return
+	}
+	if err := h.svc.store.UpdatePreferences(c.Request.Context(), UserID(c), raw); err != nil {
+		httpx.RespondError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"preferences": payload})
 }

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)