feat(uploads): HEIC/HEIF support + dynamic format hint on guest upload (#821)

Two of the three things from #821:

- HEIC/HEIF (iPhone) can now be enabled. Sharp's bundled libvips decodes `heif`
  input (verified: sharp.format.heif.input.file === true on 0.34.3 / libvips
  8.17.1), so thumbnails generate. Added heic/heif to EXTENSION_TO_MIME in both
  the backend (uploadSettings.js) and the frontend (fileTypes.ts) maps, which
  are kept in sync. (iOS Safari usually transcodes HEIC→JPEG at file selection,
  but a genuine .heic upload is now handled when it arrives.)

- The upload requirements hint no longer hardcodes "JPEG, PNG or WebP". New
  extensionsToLabel() renders the actually-configured, supported formats (e.g.
  "JPG, PNG, WEBP, MOV"), and upload.fileRequirements interpolates {{formats}}
  across all 8 locales. Unsupported extensions are dropped from the label so it
  never advertises a format the backend would reject.

DNG / camera RAW is deliberately NOT included: Sharp's libvips has no raw loader,
so a DNG would upload then fail thumbnailing (photo → 'failed', no preview).
Proper RAW support (embedded-preview extraction) is a separate PR.

Adds vitest coverage for extensionsToLabel + the HEIC mapping.

frontend/src/components/gallery/UserPhotoUpload.tsx

@@ -5,7 +5,7 @@ import { toast } from 'react-toastify';
 import { Button } from '../common';
 import { api } from '../../config/api';
 import { usePublicSettings } from '../../hooks/usePublicSettings';
-import { extensionsToMimeTypes, extensionsToAcceptString } from '../../utils/fileTypes';
+import { extensionsToMimeTypes, extensionsToAcceptString, extensionsToLabel } from '../../utils/fileTypes';
 
 interface UserPhotoUploadProps {
   eventId: number;
@@ -61,6 +61,13 @@ export const UserPhotoUpload: React.FC<UserPhotoUploadProps> = ({
     [publicSettings?.allowed_file_types]
   );
 
+  // #821 — the requirements hint used to hardcode "JPEG, PNG or WebP"; render
+  // the actually-configured formats so it never contradicts what's accepted.
+  const formatsLabel = useMemo(
+    () => extensionsToLabel(publicSettings?.allowed_file_types),
+    [publicSettings?.allowed_file_types]
+  );
+
   // Shared filter pipeline for both <input> change and drag-and-drop (#504).
   const addFiles = (incoming: File[]) => {
     const validFiles = incoming.filter((file) => {
@@ -236,7 +243,7 @@ export const UserPhotoUpload: React.FC<UserPhotoUploadProps> = ({
                     {/* #613 — pass { limit } so `{{limit}}` interpolates
                         with the real number from settings instead of
                         rendering literally. */}
-                    {t('upload.fileRequirements', { limit: maxFilesPerUpload, sizeLimit: maxFileSizeMb })}
+                    {t('upload.fileRequirements', { formats: formatsLabel, limit: maxFilesPerUpload, sizeLimit: maxFileSizeMb })}
                   </p>
                   <input
                     type="file"

frontend/src/i18n/locales/de.json

@@ -159,7 +159,7 @@
     "noCategory": "Keine Kategorie",
     "eventSpecific": "(Veranstaltungsspezifisch)",
     "clickToUpload": "Klicken zum Hochladen oder per Drag & Drop",
-    "fileRequirements": "JPEG, PNG oder WebP (max. {{sizeLimit}}MB pro Datei, {{limit}} Dateien pro Upload)",
+    "fileRequirements": "{{formats}} (max. {{sizeLimit}}MB pro Datei, {{limit}} Dateien pro Upload)",
     "selectedFiles": "Ausgewählte Dateien",
     "uploading": "Wird hochgeladen...",
     "transferring": "Übertragung",

frontend/src/i18n/locales/en.json

@@ -159,7 +159,7 @@
     "noCategory": "No category",
     "eventSpecific": "(Event specific)",
     "clickToUpload": "Click to upload or drag and drop",
-    "fileRequirements": "JPEG, PNG or WebP (max {{sizeLimit}}MB per file, {{limit}} files per upload)",
+    "fileRequirements": "{{formats}} (max {{sizeLimit}}MB per file, {{limit}} files per upload)",
     "selectedFiles": "Selected files",
     "uploading": "Uploading...",
     "transferring": "Transferring",

frontend/src/i18n/locales/es.json

@@ -126,7 +126,7 @@
     "noCategory": "Sin categoría",
     "eventSpecific": "(Específico del evento)",
     "clickToUpload": "Haz clic para subir o arrastra y suelta",
-    "fileRequirements": "JPEG, PNG o WebP (máx. {{sizeLimit}}MB por archivo, {{limit}} archivos por subida)",
+    "fileRequirements": "{{formats}} (máx. {{sizeLimit}}MB por archivo, {{limit}} archivos por subida)",
     "fileRequirementsMedia": "Imágenes JPEG, PNG o WebP y videos MP4/MOV/WEBM (máx. 50MB por archivo, {{limit}} archivos por subida)",
     "unsupportedFiles": "Algunos archivos se omitieron porque el formato no es compatible (usa JPEG/PNG/WebP/MP4/MOV/WEBM).",
     "selectedFiles": "Archivos seleccionados",

frontend/src/i18n/locales/fr.json

@@ -131,7 +131,7 @@
     "noCategory": "Aucune catégorie",
     "eventSpecific": "(Spécifique à l'événement)",
     "clickToUpload": "Cliquez pour téléverser ou glissez-déposez",
-    "fileRequirements": "JPEG, PNG ou WebP (max {{sizeLimit}} Mo par fichier, {{limit}} fichiers par téléversement)",
+    "fileRequirements": "{{formats}} (max {{sizeLimit}} Mo par fichier, {{limit}} fichiers par téléversement)",
     "selectedFiles": "Fichiers sélectionnés",
     "uploading": "Téléversement en cours...",
     "transferring": "Transfert en cours",

frontend/src/i18n/locales/nl.json

@@ -131,7 +131,7 @@
     "noCategory": "Geen categorie",
     "eventSpecific": "(Evenement-specifiek)",
     "clickToUpload": "Klik om te uploaden of sleep bestanden hierheen",
-    "fileRequirements": "JPEG, PNG of WebP (max. {{sizeLimit}} MB per bestand, {{limit}} bestanden per upload)",
+    "fileRequirements": "{{formats}} (max. {{sizeLimit}} MB per bestand, {{limit}} bestanden per upload)",
     "selectedFiles": "Geselecteerde bestanden",
     "uploading": "Uploaden...",
     "uploadComplete": "Upload voltooid!",

frontend/src/i18n/locales/pt.json

@@ -131,7 +131,7 @@
     "noCategory": "Sem categoria",
     "eventSpecific": "(Específico do evento)",
     "clickToUpload": "Clique para enviar ou arraste e solte",
-    "fileRequirements": "JPEG, PNG ou WebP (máx. {{sizeLimit}}MB por arquivo, {{limit}} arquivos por envio)",
+    "fileRequirements": "{{formats}} (máx. {{sizeLimit}}MB por arquivo, {{limit}} arquivos por envio)",
     "selectedFiles": "Arquivos selecionados",
     "uploading": "Enviando...",
     "uploadComplete": "Envio concluído!",

frontend/src/i18n/locales/ru.json

@@ -131,7 +131,7 @@
     "noCategory": "Без категории",
     "eventSpecific": "(Для конкретного события)",
     "clickToUpload": "Нажмите для загрузки или перетащите файлы",
-    "fileRequirements": "JPEG, PNG или WebP (макс. {{sizeLimit}} МБ на файл, {{limit}} файлов за загрузку)",
+    "fileRequirements": "{{formats}} (макс. {{sizeLimit}} МБ на файл, {{limit}} файлов за загрузку)",
     "selectedFiles": "Выбранные файлы",
     "uploading": "Загрузка...",
     "uploadComplete": "Загрузка завершена!",

frontend/src/i18n/locales/sl.json

@@ -131,7 +131,7 @@
     "noCategory": "Brez kategorije",
     "eventSpecific": "(specifično za dogodek)",
     "clickToUpload": "Kliknite za nalaganje ali povlecite in spustite",
-    "fileRequirements": "JPEG, PNG ali WebP (največ {{sizeLimit}} MB na datoteko, {{limit}} datotek na nalaganje)",
+    "fileRequirements": "{{formats}} (največ {{sizeLimit}} MB na datoteko, {{limit}} datotek na nalaganje)",
     "selectedFiles": "Izbrane datoteke",
     "uploading": "Nalaganje...",
     "transferring": "Prenašanje",

frontend/src/utils/__tests__/fileTypes.test.ts

@@ -0,0 +1,35 @@
+import { describe, it, expect } from 'vitest';
+import { extensionsToMimeTypes, extensionsToAcceptString, extensionsToLabel } from '../fileTypes';
+
+describe('fileTypes', () => {
+  describe('extensionsToMimeTypes', () => {
+    it('maps known extensions to MIME types', () => {
+      expect(extensionsToMimeTypes('jpg,png,mov')).toEqual(['image/jpeg', 'image/png', 'video/quicktime']);
+    });
+    it('supports HEIC/HEIF (#821)', () => {
+      expect(extensionsToMimeTypes('heic,heif')).toEqual(['image/heic', 'image/heif']);
+    });
+    it('drops unknown extensions and falls back to default when nothing maps', () => {
+      expect(extensionsToMimeTypes('dng,xyz')).toEqual(['image/jpeg', 'image/png', 'image/webp']);
+    });
+  });
+
+  describe('extensionsToLabel', () => {
+    it('renders a de-duplicated, upper-cased list of the configured formats', () => {
+      expect(extensionsToLabel('jpg,jpeg,png,webp,mov')).toBe('JPG, JPEG, PNG, WEBP, MOV');
+    });
+    it('only lists supported extensions (drops unknowns like dng)', () => {
+      expect(extensionsToLabel('jpg,png,dng')).toBe('JPG, PNG');
+    });
+    it('falls back to the default set when empty', () => {
+      expect(extensionsToLabel('')).toBe('JPG, JPEG, PNG, WEBP');
+      expect(extensionsToLabel(null)).toBe('JPG, JPEG, PNG, WEBP');
+    });
+  });
+
+  describe('extensionsToAcceptString', () => {
+    it('joins MIME types for the input accept attribute', () => {
+      expect(extensionsToAcceptString('jpg,heic')).toBe('image/jpeg,image/heic');
+    });
+  });
+});

frontend/src/utils/fileTypes.ts

@@ -12,6 +12,9 @@ const EXTENSION_TO_MIME: Record<string, string> = {
   webm: 'video/webm',
   mov: 'video/quicktime',
   avi: 'video/x-msvideo',
+  // HEIC/HEIF (iPhone) — kept in sync with the backend EXTENSION_TO_MIME.
+  heic: 'image/heic',
+  heif: 'image/heif',
 };
 
 const DEFAULT_ALLOWED = 'jpg,jpeg,png,webp';
@@ -46,3 +49,24 @@ export function extensionsToMimeTypes(extString?: string | null): string[] {
 export function extensionsToAcceptString(extString?: string | null): string {
   return extensionsToMimeTypes(extString).join(',');
 }
+
+/**
+ * Human-readable, de-duplicated list of the configured extensions for the
+ * upload requirements hint, e.g. "JPG, PNG, WEBP, MOV". Only extensions the
+ * app actually supports (present in EXTENSION_TO_MIME) are shown, so the hint
+ * never advertises a format the backend would reject.
+ */
+export function extensionsToLabel(extString?: string | null): string {
+  const input = extString?.trim() || DEFAULT_ALLOWED;
+  const seen = new Set<string>();
+  const labels: string[] = [];
+  input.split(',').forEach(ext => {
+    const cleaned = ext.trim().toLowerCase().replace(/^\./, '');
+    if (cleaned && EXTENSION_TO_MIME[cleaned] && !seen.has(cleaned)) {
+      seen.add(cleaned);
+      labels.push(cleaned.toUpperCase());
+    }
+  });
+  if (labels.length === 0) return extensionsToLabel(DEFAULT_ALLOWED);
+  return labels.join(', ');
+}