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

backend/src/app.ts

@@ -8,6 +8,7 @@ import { shoppingRoutes } from './routes/shopping.js';
 import { tagRoutes } from './routes/tags.js';
 import { imageRoutes } from './routes/images.js';
 import { botRoutes } from './routes/bot.js';
+import { ogScrapeRoutes } from './routes/og-scrape.js';
 
 export async function buildApp() {
   const app = Fastify({ logger: true });
@@ -39,5 +40,8 @@ export async function buildApp() {
   await app.register(botRoutes);
   await app.after();
 
+  await app.register(ogScrapeRoutes);
+  await app.after();
+
   return app;
 }

backend/src/routes/og-scrape.ts

@@ -0,0 +1,76 @@
+import { FastifyInstance } from 'fastify';
+import { scrapeOgData } from '../services/og-scraper.service.js';
+import { getDb } from '../db/connection.js';
+import sharp from 'sharp';
+import fs from 'fs';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const DATA_DIR = path.resolve(__dirname, '../../data');
+
+export async function ogScrapeRoutes(app: FastifyInstance) {
+  // Preview: Just fetch OG data without downloading
+  app.get('/api/og-preview', async (request, reply) => {
+    const { url } = request.query as { url?: string };
+    if (!url) return reply.status(400).send({ error: 'url parameter required' });
+
+    try {
+      const data = await scrapeOgData(url);
+      return data;
+    } catch (err: any) {
+      return reply.status(502).send({ error: `Failed to scrape: ${err.message}` });
+    }
+  });
+
+  // Download OG image and attach to recipe
+  app.post('/api/recipes/:id/fetch-image', async (request, reply) => {
+    const { id } = request.params as { id: string };
+    const { url } = request.body as { url: string };
+
+    if (!url) return reply.status(400).send({ error: 'url required' });
+
+    const db = getDb();
+    const recipe = db.prepare('SELECT id FROM recipes WHERE id = ?').get(id) as any;
+    if (!recipe) return reply.status(404).send({ error: 'Recipe not found' });
+
+    try {
+      // Scrape OG data
+      const ogData = await scrapeOgData(url);
+      if (!ogData.image) return reply.status(404).send({ error: 'No image found at URL' });
+
+      // Download image
+      const imgRes = await fetch(ogData.image, {
+        headers: { 'User-Agent': 'Mozilla/5.0' },
+        signal: AbortSignal.timeout(15000),
+      });
+      if (!imgRes.ok) throw new Error(`Image download failed: ${imgRes.status}`);
+
+      const buffer = Buffer.from(await imgRes.arrayBuffer());
+
+      // Process with sharp → WebP, max 1200px wide
+      const imgDir = path.join(DATA_DIR, 'images', 'recipes', id);
+      fs.mkdirSync(imgDir, { recursive: true });
+      const imgPath = path.join(imgDir, 'hero.webp');
+
+      await sharp(buffer)
+        .resize(1200, null, { withoutEnlargement: true })
+        .webp({ quality: 85 })
+        .toFile(imgPath);
+
+      // Update recipe
+      const imageUrl = `/images/recipes/${id}/hero.webp`;
+      db.prepare('UPDATE recipes SET image_url = ?, source_url = ?, updated_at = datetime(\'now\') WHERE id = ?')
+        .run(imageUrl, url, id);
+
+      return {
+        ok: true,
+        image_url: imageUrl,
+        og_title: ogData.title,
+        og_description: ogData.description,
+      };
+    } catch (err: any) {
+      return reply.status(502).send({ error: `Failed: ${err.message}` });
+    }
+  });
+}

backend/src/services/og-scraper.service.ts

@@ -0,0 +1,73 @@
+/**
+ * OG Image Scraper — holt og:image aus beliebiger URL
+ * Funktioniert mit Pinterest, Chefkoch, Allrecipes, Blogs etc.
+ */
+
+const USER_AGENTS: Record<string, string> = {
+  'pinterest.com': 'Twitterbot/1.0',
+  'pinterest.de': 'Twitterbot/1.0',
+  'pin.it': 'Twitterbot/1.0',
+  default: 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
+};
+
+function getUserAgent(url: string): string {
+  for (const [domain, ua] of Object.entries(USER_AGENTS)) {
+    if (domain !== 'default' && url.includes(domain)) return ua;
+  }
+  return USER_AGENTS.default;
+}
+
+export interface OgData {
+  image?: string;
+  title?: string;
+  description?: string;
+}
+
+export async function scrapeOgData(url: string): Promise<OgData> {
+  const ua = getUserAgent(url);
+
+  const res = await fetch(url, {
+    headers: { 'User-Agent': ua },
+    redirect: 'follow',
+    signal: AbortSignal.timeout(10000),
+  });
+
+  if (!res.ok) throw new Error(`HTTP ${res.status}`);
+
+  const html = await res.text();
+  const result: OgData = {};
+
+  // Extract og:image
+  const imageMatch = html.match(/<meta[^>]+(?:property|name)="og:image"[^>]+content="([^"]+)"/i)
+    || html.match(/<meta[^>]+content="([^"]+)"[^>]+(?:property|name)="og:image"/i);
+  if (imageMatch) result.image = imageMatch[1];
+
+  // Extract og:title
+  const titleMatch = html.match(/<meta[^>]+(?:property|name)="og:title"[^>]+content="([^"]+)"/i)
+    || html.match(/<meta[^>]+content="([^"]+)"[^>]+(?:property|name)="og:title"/i);
+  if (titleMatch) result.title = decodeHtmlEntities(titleMatch[1]);
+
+  // Extract og:description
+  const descMatch = html.match(/<meta[^>]+(?:property|name)="og:description"[^>]+content="([^"]+)"/i)
+    || html.match(/<meta[^>]+content="([^"]+)"[^>]+(?:property|name)="og:description"/i);
+  if (descMatch) result.description = decodeHtmlEntities(descMatch[1]);
+
+  // Pinterest special: higher-res image from JSON data
+  if (url.includes('pinterest') && result.image) {
+    // Try to get orig resolution instead of 736x
+    const origMatch = html.match(/"orig":\s*\{[^}]*"url"\s*:\s*"([^"]+)"/);
+    if (origMatch) result.image = origMatch[1];
+  }
+
+  return result;
+}
+
+function decodeHtmlEntities(str: string): string {
+  return str
+    .replace(/&amp;/g, '&')
+    .replace(/&lt;/g, '<')
+    .replace(/&gt;/g, '>')
+    .replace(/&quot;/g, '"')
+    .replace(/&#39;/g, "'")
+    .replace(/&#x27;/g, "'");
+}

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>
+          <div className="flex gap-2">
             <input
               type="url"
               value={sourceUrl}
               onChange={e => setSourceUrl(e.target.value)}
               placeholder="https://pinterest.com/..."
-            className={inputClass}
+              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 */}