feat: notifications system, webhook retry, issue assign endpoint, CLI milestones/notifications/overdue commands

app/models/notification.py

@@ -0,0 +1,20 @@
+from sqlalchemy import Column, Integer, String, Text, DateTime, Boolean, ForeignKey
+from sqlalchemy.sql import func
+from sqlalchemy.orm import relationship
+from app.core.config import Base
+
+
+class Notification(Base):
+    __tablename__ = "notifications"
+
+    id = Column(Integer, primary_key=True, index=True)
+    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)
+    type = Column(String(50), nullable=False)  # issue.assigned, issue.mentioned, comment.added, milestone.due
+    title = Column(String(255), nullable=False)
+    message = Column(Text, nullable=True)
+    entity_type = Column(String(50), nullable=True)  # issue, comment, milestone
+    entity_id = Column(Integer, nullable=True)
+    is_read = Column(Boolean, default=False)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+
+    user = relationship("User")