Mejoras de sesion: estabilizacion, IA, Nexus Yonke y marketplace B2B

- F0 blindaje: Redis/Celery, pg_hba sin trust LAN, secretos a env 600, backups, webhook auth, jobs muertos
- F1 caja: bugs POS, reembolsos al corte, apartados, CFDI, topes de descuento en cotizacion/apartado
- F2/F7 IA de catalogo: autocategorizacion, dedup de SKUs con embeddings, OCR de facturas, descripciones, claves SAT, limpieza de fitment
- F3 IA en el flujo: vision Yonke, preguntas MeLi, venta cruzada, anomalias, sinonimos, busqueda semantica (rerank/embeddings)
- F4/F8 escala y cartera: /metrics+Prometheus+Grafana, pool, score de credito, churn, metricas multi-tenant
- Nexus Yonke (M1-M6): modelo de datos 1-de-1, alta por donador, vitrina publica, MeLi usado, consignacion, garantia por dias, reportes, etiquetas
- Marketplace B2B entre yonkes (catalogo + pedidos cross-tenant)
- Seguridad: auth en /api/admin/* (35 endpoints), alertas por tenant
- Migraciones v4.27/v4.28; timers expire-demos y rollup-metrics

pos/services/wa_quotation.py

@@ -96,17 +96,106 @@ def detect_quote_intent(text, has_open_quote=False):
     return None, None
 
 
-def confirm_quotation(tenant_conn, phone):
-    """Mark the open quotation as confirmed/accepted."""
+def confirm_quotation(tenant_conn, phone, customer_id=None, tenant_id=None, branch_id=None):
+    """Confirm the open quotation and convert it into a pending-payment sale.
+
+    - Validates stock for every line before touching anything.
+    - Creates the sale via pos_engine.process_sale (status 'pending_payment',
+      stock reserved, no cash movement — payable later at the counter).
+    - Notifies owners via the notification engine (best effort).
+
+    Returns dict {'quotation_id', 'sale_id', 'total', 'items'} on success,
+    dict {'error': ..., ...} on failure, or None if there was no open quote.
+    """
     qid = get_open_quotation(tenant_conn, phone)
     if not qid:
         return None
+
+    detail = get_quotation_detail(tenant_conn, qid)
+    if not detail or not detail.get('items'):
+        return None
+
+    # Resolve target branch (first active)
+    if not branch_id:
+        cur = tenant_conn.cursor()
+        cur.execute("SELECT id FROM branches ORDER BY id LIMIT 1")
+        row = cur.fetchone()
+        cur.close()
+        if not row:
+            return {'error': 'no_branch', 'quotation_id': qid}
+        branch_id = row[0]
+
+    # Resolve inventory ids and validate stock
+    cur = tenant_conn.cursor()
+    resolved = []
+    for it in detail['items']:
+        cur.execute("""
+            SELECT i.id, COALESCE(s.stock, 0) FROM inventory i
+            LEFT JOIN (
+                SELECT inventory_id, SUM(stock) AS stock FROM inventory_stock
+                GROUP BY inventory_id
+            ) s ON s.inventory_id = i.id
+            WHERE i.part_number = %s AND i.is_active LIMIT 1
+        """, (it['part_number'],))
+        row = cur.fetchone()
+        if not row:
+            cur.close()
+            return {'error': 'item_not_found', 'part_number': it['part_number'],
+                    'quotation_id': qid}
+        inv_id, stock = row
+        if (stock or 0) < it['quantity']:
+            cur.close()
+            return {'error': 'insufficient_stock', 'part_number': it['part_number'],
+                    'available': int(stock or 0), 'requested': it['quantity'],
+                    'quotation_id': qid}
+        resolved.append({
+            'inventory_id': inv_id,
+            'quantity': it['quantity'],
+            'unit_price': it['unit_price'],
+            'tax_rate': it['tax_rate'],
+            'discount_pct': 0,
+        })
+    cur.close()
+
+    from services.pos_engine import process_sale
+    sale_data = {
+        'items': resolved,
+        'customer_id': customer_id,
+        'payment_method': 'pendiente',
+        'sale_type': 'cash',
+        'branch_id': branch_id,
+        'amount_paid': 0,
+        'notes': f'Pedido por WhatsApp (cotizacion #{qid})',
+    }
+    try:
+        sale = process_sale(tenant_conn, sale_data)
+    except ValueError as e:
+        tenant_conn.rollback()
+        return {'error': 'sale_failed', 'message': str(e), 'quotation_id': qid}
+    except Exception:
+        tenant_conn.rollback()
+        raise
+
     cur = tenant_conn.cursor()
     cur.execute("UPDATE quotations SET status = 'converted' WHERE id = %s", (qid,))
-    tenant_conn.commit()
     cur.close()
+    tenant_conn.commit()
     clear_last_shown(tenant_conn, phone)
-    return qid
+
+    # Notify owners (best effort — never block the reply)
+    try:
+        if tenant_id:
+            from services.notification_engine import notify_new_sale
+            notify_new_sale(tenant_conn, tenant_id, sale['id'], sale['total'], 'whatsapp')
+    except Exception:
+        pass
+
+    return {
+        'quotation_id': qid,
+        'sale_id': sale['id'],
+        'total': sale['total'],
+        'items': detail['items'],
+    }
 
 
 # ─── Persistent last-shown-part per phone ────────────────────────────