feat: Funcion de sistema tenants

backend/app/core/database.py

@@ -6,7 +6,9 @@ SQLAlchemy 2.0 async setup con PostgreSQL
 
 from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
 from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
-from sqlalchemy import String, DateTime, func
+from sqlalchemy import String, DateTime, func, text
+from sqlalchemy.types import TypeDecorator, CHAR
+from sqlalchemy.dialects.postgresql import UUID as PG_UUID
 from typing import AsyncGenerator
 import uuid
 from datetime import datetime
@@ -34,18 +36,46 @@ AsyncSessionLocal = async_sessionmaker(
     autoflush=True,
     autocommit=False
 )
+class GUID(TypeDecorator):
+    """UUID portable: UUID nativo en Postgres, CHAR(36) en otros dialectos (SQLite para tests)."""
+
+    impl = CHAR
+    cache_ok = True
+
+    def load_dialect_impl(self, dialect):
+        if dialect.name == "postgresql":
+            return dialect.type_descriptor(PG_UUID(as_uuid=True))
+        return dialect.type_descriptor(CHAR(36))
+
+    def process_bind_param(self, value, dialect):
+        if value is None:
+            return None
+
+        if dialect.name == "postgresql":
+            return value
+
+        if isinstance(value, uuid.UUID):
+            return str(value)
+        return str(uuid.UUID(str(value)))
+
+    def process_result_value(self, value, dialect):
+        if value is None:
+            return None
+        if isinstance(value, uuid.UUID):
+            return value
+        return uuid.UUID(str(value))
 
 
 class Base(DeclarativeBase):
     """Base class para todos los modelos SQLAlchemy."""
-    
+
     # Columnas comunes para auditoría
-    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, default=uuid.uuid4)
+    id: Mapped[uuid.UUID] = mapped_column(GUID(), primary_key=True, default=uuid.uuid4)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
     updated_at: Mapped[datetime] = mapped_column(
-        DateTime(timezone=True), 
+        DateTime(timezone=True),
         server_default=func.now(),
-        onupdate=func.now()
+        onupdate=func.now(),
     )
 
 
@@ -89,7 +119,7 @@ async def check_database_health() -> bool:
     """
     try:
         async with AsyncSessionLocal() as session:
-            await session.execute("SELECT 1")
+            await session.execute(text("SELECT 1"))
             return True
     except Exception:
         return False