feat: duplicate detection + original URL in description

- Add original recipe URL to Mealie description (appended after blank line)
- Check for duplicate recipes on scrape (match orgURL or URL in description)
- Show warning with link to existing recipe if duplicate found
- User can still import anyway (warning only, not blocking)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/main.py

@@ -81,7 +81,19 @@ def scrape_url():
         return jsonify({"ok": False, "error": "Nincs URL megadva."})
     try:
         data = scrape(url)
-        return jsonify({"ok": True, "data": data})
+
+        # Check for duplicate in Mealie
+        duplicate = None
+        cfg = config.load()
+        if cfg.get("mealie_url") and cfg.get("mealie_api_key"):
+            try:
+                client = MealieClient(cfg["mealie_url"], cfg["mealie_api_key"],
+                                      api_url=config.MEALIE_INTERNAL_URL)
+                duplicate = client.find_duplicate(url, data.get("title", ""))
+            except Exception:
+                pass  # non-fatal
+
+        return jsonify({"ok": True, "data": data, "duplicate": duplicate})
     except Exception as exc:
         return jsonify({"ok": False, "error": str(exc), "trace": traceback.format_exc()})