feat: OG image scraper - auto-fetch recipe images from Pinterest/URLs

- New backend service: og-scraper.service.ts (extracts og:image, og:title, og:description)
- Pinterest support via Twitterbot UA (gets original resolution from i.pinimg.com)
- Works with Chefkoch, Allrecipes, blogs, any site with og:image meta tags
- GET /api/og-preview?url= for preview
- POST /api/recipes/:id/fetch-image to download + process with sharp
- Frontend: 'Bild holen' button appears when source URL is filled
- Auto-fills title & description from OG data if empty
- Images processed to WebP, max 1200px wide

frontend/src/api/recipes.ts

@@ -72,3 +72,20 @@ export function uploadRecipeImage(id: string, file: File) {
     return r.json() as Promise<{ image_url: string }>
   })
 }
+
+export interface OgData {
+  image?: string
+  title?: string
+  description?: string
+}
+
+export function fetchOgPreview(url: string) {
+  return apiFetch<OgData>(`/og-preview?url=${encodeURIComponent(url)}`)
+}
+
+export function fetchImageFromUrl(recipeId: string, url: string) {
+  return apiFetch<{ ok: boolean; image_url: string; og_title?: string; og_description?: string }>(
+    `/recipes/${recipeId}/fetch-image`,
+    { method: 'POST', body: JSON.stringify({ url }) }
+  )
+}

frontend/src/pages/RecipeFormPage.tsx

@@ -2,8 +2,8 @@ import { useState, useEffect, useRef } from 'react'
 import { useParams, useNavigate } from 'react-router'
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
 import toast from 'react-hot-toast'
-import { ArrowLeft, Plus, Trash2, Camera, X, GripVertical } from 'lucide-react'
-import { fetchRecipe, createRecipe, updateRecipe, deleteRecipe, uploadRecipeImage } from '../api/recipes'
+import { ArrowLeft, Plus, Trash2, Camera, X, GripVertical, Link, Loader2 } from 'lucide-react'
+import { fetchRecipe, createRecipe, updateRecipe, deleteRecipe, uploadRecipeImage, fetchOgPreview } from '../api/recipes'
 import { fetchCategories } from '../api/categories'
 import type { RecipeFormData } from '../api/recipes'
 import type { Ingredient, Step } from '../api/types'
@@ -61,6 +61,7 @@ export function RecipeFormPage() {
     { key: nextKey(), instruction: '' },
   ])
   const [showDeleteConfirm, setShowDeleteConfirm] = useState(false)
+  const [fetchingOg, setFetchingOg] = useState(false)
 
   // Populate form when editing
   useEffect(() => {
@@ -331,16 +332,51 @@ export function RecipeFormPage() {
           </div>
         </div>
 
-        {/* Source URL */}
+        {/* Source URL + OG Fetch */}
         <div>
           <label className={labelClass}>Quelle (URL)</label>
-          <input
-            type="url"
-            value={sourceUrl}
-            onChange={e => setSourceUrl(e.target.value)}
-            placeholder="https://pinterest.com/..."
-            className={inputClass}
-          />
+          <div className="flex gap-2">
+            <input
+              type="url"
+              value={sourceUrl}
+              onChange={e => setSourceUrl(e.target.value)}
+              placeholder="https://pinterest.com/..."
+              className={`${inputClass} flex-1`}
+            />
+            {sourceUrl.trim() && !imagePreview && (
+              <button
+                type="button"
+                disabled={fetchingOg}
+                onClick={async () => {
+                  setFetchingOg(true)
+                  try {
+                    const og = await fetchOgPreview(sourceUrl.trim())
+                    if (og.image) {
+                      setImagePreview(og.image)
+                      setImageUrl(og.image)
+                      toast.success('Bild gefunden! 📸')
+                    } else {
+                      toast.error('Kein Bild auf der Seite gefunden')
+                    }
+                    // Auto-fill title & description if empty
+                    if (!title.trim() && og.title) setTitle(og.title)
+                    if (!description.trim() && og.description) setDescription(og.description)
+                  } catch {
+                    toast.error('Konnte die Seite nicht laden')
+                  } finally {
+                    setFetchingOg(false)
+                  }
+                }}
+                className="bg-secondary text-white px-4 py-3 rounded-xl font-medium min-h-[44px] min-w-[44px] flex items-center justify-center disabled:opacity-50 whitespace-nowrap gap-2"
+              >
+                {fetchingOg ? <Loader2 size={18} className="animate-spin" /> : <Link size={18} />}
+                {!fetchingOg && <span className="hidden sm:inline text-sm">Bild holen</span>}
+              </button>
+            )}
+          </div>
+          {sourceUrl.trim() && (
+            <p className="text-xs text-warm-grey mt-1">💡 Pinterest, Chefkoch, Blogs — Bild wird automatisch geholt</p>
+          )}
         </div>
 
         {/* Ingredients */}