feat(phase-1): Complete foundation setup

- Add User model and authentication system with JWT cookies
- Implement login/logout routes and protected dashboard
- Add Alembic database migration configuration
- Add create_admin.py script for initial user setup
- Make ContentGenerator and ImageGenerator lazy-initialized
- Add comprehensive API keys setup documentation
- Fix startup errors when services unavailable

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/models/__init__.py

@@ -4,6 +4,7 @@ Modelos de base de datos SQLAlchemy.
 
 from app.core.database import Base
 
+from app.models.user import User
 from app.models.product import Product
 from app.models.service import Service
 from app.models.tip_template import TipTemplate
@@ -14,6 +15,7 @@ from app.models.interaction import Interaction
 
 __all__ = [
     "Base",
+    "User",
     "Product",
     "Service",
     "TipTemplate",

app/models/user.py

@@ -0,0 +1,49 @@
+"""
+Modelo de Usuario para autenticación del dashboard.
+"""
+
+from datetime import datetime
+from sqlalchemy import Column, Integer, String, Boolean, DateTime
+
+from app.core.database import Base
+
+
+class User(Base):
+    """Modelo para usuarios del dashboard."""
+
+    __tablename__ = "users"
+
+    id = Column(Integer, primary_key=True, index=True)
+
+    # Credenciales
+    username = Column(String(50), unique=True, nullable=False, index=True)
+    email = Column(String(255), unique=True, nullable=False, index=True)
+    hashed_password = Column(String(255), nullable=False)
+
+    # Información
+    full_name = Column(String(255), nullable=True)
+
+    # Estado
+    is_active = Column(Boolean, default=True)
+    is_superuser = Column(Boolean, default=False)
+
+    # Timestamps
+    last_login = Column(DateTime, nullable=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+
+    def __repr__(self):
+        return f"<User {self.username}>"
+
+    def to_dict(self):
+        """Convertir a diccionario (sin password)."""
+        return {
+            "id": self.id,
+            "username": self.username,
+            "email": self.email,
+            "full_name": self.full_name,
+            "is_active": self.is_active,
+            "is_superuser": self.is_superuser,
+            "last_login": self.last_login.isoformat() if self.last_login else None,
+            "created_at": self.created_at.isoformat() if self.created_at else None
+        }