feat(fin,ops): Facturación y Cobranza (Diag. 4), bitácora de embarque (Diag. 3) y subida a MinIO

- schema fin: fin.invoices + fin.invoice_items + fin.payments; totales con IVA,
  estados borrador→emitida→enviada→pagada, cobranza (pagos) y saldo automático
- generar-factura-desde-embarque (toma conceptos de venta de la cotización)
- ops.shipment_events: bitácora/hitos del embarque con secuencia por defecto
  según operación (importación/exportación) — cubre Diagrama 3
- subida de documentos a MinIO: POST /crm/uploads (multipart) + URL firmada
- migración c4d5e6f7a8b9, routers/permisos (fin), seed del flujo hasta factura
- 58 tests pytest en verde

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/tests/conftest.py

@@ -37,8 +37,9 @@ import api.v1.modules.crm.quotes.models  # noqa: E402,F401
 import api.v1.modules.crm.service_requests.models  # noqa: E402,F401
 import api.v1.modules.crm.suppliers.models  # noqa: E402,F401
 import api.v1.modules.ops.shipments.models  # noqa: E402,F401
+import api.v1.modules.fin.invoices.models  # noqa: E402,F401
 
-_SCHEMA_MAP = {"crm": None, "core": None, "ops": None}
+_SCHEMA_MAP = {"crm": None, "core": None, "ops": None, "fin": None}
 
 # Tabla mínima core.tenants para resolver la FK tenant_id de las tablas crm.
 # En CI (PostgreSQL) la tabla real la crea la migración inicial del core.

backend/tests/test_invoices.py

@@ -0,0 +1,52 @@
+from decimal import Decimal
+
+from api.v1.modules.crm.accounts import service as accounts_service
+from api.v1.modules.crm.accounts.dto import AccountCreate
+from api.v1.modules.crm.quotes import service as quotes_service
+from api.v1.modules.crm.quotes.dto import QuoteCreate, QuoteItemCreate
+from api.v1.modules.fin.invoices import service
+from api.v1.modules.fin.invoices.dto import InvoiceCreate, InvoiceItemCreate, PaymentCreate
+from api.v1.modules.ops.shipments import service as shipments_service
+from api.v1.modules.ops.shipments.dto import ShipmentCreate
+
+T, C = 1, 1
+
+
+def test_invoice_totals_with_tax(db):
+    inv = service.create_invoice(db, InvoiceCreate(reference="F-001", currency="MXN", tax_rate=Decimal("16")), T, C)
+    service.create_item(db, InvoiceItemCreate(invoice_id=inv.id, concept="flete_internacional", quantity=1, unit_amount=1000), T, C)
+    service.create_item(db, InvoiceItemCreate(invoice_id=inv.id, concept="despacho_aduanal", quantity=1, unit_amount=500), T, C)
+    inv = service.get_invoice(db, inv.id, T, C)
+    assert float(inv.subtotal) == 1500.0
+    assert float(inv.tax_amount) == 240.0  # 16% de 1500
+    assert float(inv.total) == 1740.0
+    assert float(inv.balance) == 1740.0
+
+
+def test_payment_marks_paid(db):
+    inv = service.create_invoice(db, InvoiceCreate(reference="F-002", tax_rate=Decimal("0")), T, C)
+    service.create_item(db, InvoiceItemCreate(invoice_id=inv.id, concept="otros", quantity=1, unit_amount=1000), T, C)
+    service.emit_invoice(db, inv.id, T, C)
+    service.create_payment(db, PaymentCreate(invoice_id=inv.id, amount=Decimal("400"), method="transferencia"), T, C)
+    inv = service.get_invoice(db, inv.id, T, C)
+    assert float(inv.paid_amount) == 400.0 and float(inv.balance) == 600.0
+    assert inv.status == "emitida"
+    service.create_payment(db, PaymentCreate(invoice_id=inv.id, amount=Decimal("600")), T, C)
+    inv = service.get_invoice(db, inv.id, T, C)
+    assert float(inv.balance) == 0.0 and inv.status == "pagada" and inv.paid_at is not None
+
+
+def test_generate_from_shipment_copies_quote_items(db):
+    acc = accounts_service.create_account(db, AccountCreate(name="Cliente"), T, C)
+    quote = quotes_service.create_quote(db, QuoteCreate(reference="COT-9", account_id=acc.id, currency="USD"), T, C)
+    quotes_service.create_quote_item(db, QuoteItemCreate(quote_id=quote.id, concept="flete_internacional", quantity=1, unit_cost=1000, unit_sale=1500), T, C)
+    quotes_service.accept_quote(db, quote.id, T, C)
+    shipment = shipments_service.create_shipment_from_quote(db, quote.id, T, C)
+
+    inv = service.generate_from_shipment(db, shipment.id, T, C)
+    assert inv.shipment_id == shipment.id
+    assert inv.account_id == acc.id
+    assert inv.currency == "USD"
+    items = service.get_items(db, inv.id, T, C)
+    assert len(items) == 1 and float(items[0].unit_amount) == 1500.0
+    assert float(inv.subtotal) == 1500.0

backend/tests/test_shipment_events.py

@@ -0,0 +1,34 @@
+import pytest
+from fastapi import HTTPException
+
+from api.v1.modules.ops.shipments import service
+from api.v1.modules.ops.shipments.dto import ShipmentCreate
+
+T, C = 1, 1
+
+
+def test_seed_import_milestones(db):
+    s = service.create_shipment(db, ShipmentCreate(reference="IMP-1", operation_type="importacion"), T, C)
+    events = service.seed_default_milestones(db, s.id, T, C)
+    titles = [e.event_type for e in events]
+    assert "aviso_llegada" in titles
+    assert "despacho_importacion" in titles
+    assert "entrega" in titles
+    # idempotente: no duplica
+    again = service.seed_default_milestones(db, s.id, T, C)
+    assert len(again) == len(events)
+
+
+def test_seed_export_milestones_and_complete(db):
+    s = service.create_shipment(db, ShipmentCreate(reference="EXP-1", operation_type="exportacion"), T, C)
+    events = service.seed_default_milestones(db, s.id, T, C)
+    assert any(e.event_type == "embarque" for e in events)
+    done = service.complete_shipment_event(db, events[0].id, T, C)
+    assert done.status == "completado" and done.actual_date is not None
+
+
+def test_seed_requires_operation_type(db):
+    s = service.create_shipment(db, ShipmentCreate(reference="X-1"), T, C)  # sin operation_type
+    with pytest.raises(HTTPException) as exc:
+        service.seed_default_milestones(db, s.id, T, C)
+    assert exc.value.status_code == 422