feat: completar fases 3 y 4 del roadmap mvp (gradebook, drag-and-drop, impersonacion) y actualizar README

backend/app/models/subject.py

@@ -54,6 +54,13 @@ class Commission(db.Model):
     shift = db.Column(db.String(30), nullable=True)  # Mañana, Tarde, Vespertino, Noche
     virtual_link = db.Column(db.String(500), nullable=True)  # Link Zoom, Meet, Teams, Moodle
     active = db.Column(db.Boolean, default=True)  # Changed from is_active to active
+    
+    # Cierre de Actas y Libro de Calificaciones (Fase 3 MVP)
+    grades_closed = db.Column(db.Boolean, default=False, nullable=True)
+    grades_closed_at = db.Column(db.DateTime, nullable=True)
+    grades_closed_by = db.Column(db.Integer, db.ForeignKey('users.id', ondelete='SET NULL'), nullable=True)
+    acta_number = db.Column(db.String(50), nullable=True)
+
     created_at = db.Column(db.DateTime, default=datetime.utcnow)
     updated_at = db.Column(db.DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
     
@@ -69,6 +76,7 @@ class Commission(db.Model):
 # Relationships
     pass  # Reservation already defines the relationship back to commission
     teacher = db.relationship('User', backref='teaching_commissions', foreign_keys=[teacher_id])
+    closed_by_user = db.relationship('User', foreign_keys=[grades_closed_by])
     
     # Virtual field for teacher_name
     @property
@@ -125,6 +133,11 @@ class Commission(db.Model):
             'shift': self.shift,
             'virtual_link': self.virtual_link,
             'active': self.active,
+            'grades_closed': bool(self.grades_closed),
+            'grades_closed_at': self.grades_closed_at.isoformat() if self.grades_closed_at else None,
+            'grades_closed_by': self.grades_closed_by,
+            'closed_by_name': self.closed_by_user.name if self.closed_by_user else None,
+            'acta_number': self.acta_number,
             'created_at': self.created_at.isoformat() if self.created_at else None,
             'updated_at': self.updated_at.isoformat() if self.updated_at else None,
             'full_code': self.get_full_code(),