feat: MercadoLibre integration + inventory bulk publish + WhatsApp bridge fixes

- Add MercadoLibre OAuth, listings, orders, webhooks and category search
- New marketplace_external_bp.py, meli_service.py, marketplace_external_service.py
- New marketplace_external.html/js with ML management UI
- Inventory: bulk publish to ML with category autocomplete, listing type and shipping selectors
- Inventory: new .btn--meli styles, select/label CSS fixes
- WhatsApp bridge: rate limiting, 440/515/408 error handling, stale watchdog
- DB migration v3.4_meli_integration.sql for marketplace_listings, orders, sync_queue
- Add Celery tasks for ML sync and webhook processing
- Sidebar: MercadoLibre navigation link

pos/services/catalog_service.py

@@ -230,29 +230,42 @@ def get_engines(master_conn, model_id, year_id):
     return [{'id_mye': r[0], 'name_engine': r[1], 'trim_level': r[2] or ''} for r in rows]
 
 
-def get_categories(master_conn, mye_id):
+def get_categories(master_conn, mye_id, allowed_brands=None):
     """Get part categories that have parts for this vehicle (mye_id).
 
     Uses a subquery on vehicle_parts filtered by mye_id (indexed),
     then JOINs through parts -> part_groups -> part_categories.
     Uses COUNT with a safety LIMIT on the subquery.
+
+    If allowed_brands is provided, only counts parts that have at least one
+    aftermarket equivalent from those manufacturers.
     """
     cur = master_conn.cursor()
-    cur.execute("""
+    brand_filter = ""
+    params = [mye_id]
+    if allowed_brands:
+        brand_filter = """AND EXISTS (
+            SELECT 1 FROM aftermarket_parts ap2
+            JOIN manufacturers m2 ON m2.id_manufacture = ap2.manufacturer_id
+            WHERE ap2.oem_part_id = p.id_part AND UPPER(m2.name_manufacture) = ANY(%s)
+        )"""
+        params.append(allowed_brands)
+    cur.execute(f"""
         SELECT pc.id_part_category,
                COALESCE(pc.name_es, pc.name_part_category) AS name,
                sub.cnt
         FROM (
-            SELECT pg.category_id, COUNT(*) AS cnt
+            SELECT pg.category_id, COUNT(DISTINCT p.id_part) AS cnt
             FROM vehicle_parts vp
             JOIN parts p ON p.id_part = vp.part_id
             JOIN part_groups pg ON pg.id_part_group = p.group_id
             WHERE vp.model_year_engine_id = %s
+            {brand_filter}
             GROUP BY pg.category_id
         ) sub
         JOIN part_categories pc ON pc.id_part_category = sub.category_id
         ORDER BY name
-    """, (mye_id,))
+    """, params)
     rows = cur.fetchall()
     cur.close()
     return [{'id_part_category': r[0], 'name': translate_category(r[1]), 'part_count': r[2]} for r in rows]