test(T05): contact router, rental router, email service, rate limiting tests + retry queue

backend/app/models/email_queue.py

@@ -0,0 +1,18 @@
+"""Email queue model for failed email retry."""
+from sqlalchemy import Column, Integer, String, Text, TIMESTAMP, func
+from app.database import Base
+
+
+class EmailQueue(Base):
+    __tablename__ = "email_queue"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    to_addr = Column(String(255), nullable=False)
+    subject = Column(String(255), nullable=False)
+    html_body = Column(Text, nullable=False)
+    text_body = Column(Text)
+    reply_to = Column(String(255))
+    status = Column(String(32), default="pending", nullable=False)
+    attempts = Column(Integer, default=0, nullable=False)
+    created_at = Column(TIMESTAMP, server_default=func.now())
+    updated_at = Column(TIMESTAMP, server_default=func.now(), onupdate=func.now())