frontend añadido y backend de creacion de notas

domains/arquitecture_layer/Model.py

@@ -0,0 +1,58 @@
+# Model.py
+from sqlalchemy import Column, DateTime, String, Integer, Text, BigInteger, func
+from sqlalchemy.ext.declarative import declared_attr, as_declarative
+from datetime import datetime
+from backend.db.base import Base  # tu Base declarativa
+
+class Model_base(Base):
+    __abstract__ = True
+
+    # ID autoincremental por defecto en todos los modelos
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+
+    @declared_attr
+    def sys_created_at(cls):
+        # timestamptz + default en BD
+        return Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+    @declared_attr
+    def sys_created_by(cls):
+        return Column(String, nullable=True)
+
+    @declared_attr
+    def sys_updated_at(cls):
+        # onupdate lo pone la BD al actualizar
+        return Column(DateTime(timezone=True), onupdate=func.now(), nullable=True)
+
+    @declared_attr
+    def sys_updated_by(cls):
+        return Column(String, nullable=True)
+
+    @declared_attr
+    def sys_version(cls):
+        return Column(Integer, default=1, nullable=False)
+
+    @declared_attr
+    def sys_notes(cls):
+        return Column(Text, nullable=True)
+
+    @declared_attr
+    def sys_deleted_at(cls):
+        return Column(DateTime(timezone=True), nullable=True)
+
+    def __repr__(self):
+        id_val = getattr(self, "id", None)
+        return f"<{self.__class__.__name__} id={id_val}>"
+
+    def __str__(self):
+        cls = self.__class__.__name__
+        id_val = getattr(self, "id", None)
+        return f"{cls}(id={id_val})"
+
+    def __json__(self) -> dict:
+        out = {}
+        if not hasattr(self, "__table__"): return out
+        for c in self.__table__.columns:
+            v = getattr(self, c.name, None)
+            out[c.name] = v.isoformat() if isinstance(v, datetime) else v
+        return out