feat(bd): V016 create Rubro table con SYSTEM_VERSIONING (CAT-001)

- dbo.Rubro: adjacency list, self-FK, soft-delete, temporal retention 10y
- Filtered unique index UQ_Rubro_ParentId_Nombre_Activo + covering IX_Rubro_ParentId_Activo
- Permission catalogo:rubros:gestionar seeded + assigned to admin role
- V016_ROLLBACK.sql: full reversal script
- RubrosOptions class (MaxDepth=10) + appsettings.json Rubros section
- services.Configure<RubrosOptions> registered in Infrastructure DI
- database/README.md updated with V013-V016 entries

src/api/SIGCM2.Api/appsettings.json

@@ -32,5 +32,8 @@
     ],
     "Enrich": [ "FromLogContext", "WithMachineName", "WithThreadId" ]
   },
+  "Rubros": {
+    "MaxDepth": 10
+  },
   "AllowedHosts": "*"
 }