feat: enhance agent orchestration, knowledge flow and UI refinements

backend/app/models/reminder.py

@@ -0,0 +1,21 @@
+from enum import Enum as PyEnum
+
+from sqlalchemy import Boolean, Column, DateTime, Enum, ForeignKey, String, Text
+
+from app.models.base import BaseModel
+
+
+class ReminderStatus(str, PyEnum):
+    PENDING = "pending"
+    DONE = "done"
+
+
+class Reminder(BaseModel):
+    __tablename__ = "reminders"
+
+    user_id = Column(String(36), ForeignKey("users.id"), nullable=False, index=True)
+    title = Column(String(255), nullable=False)
+    note = Column(Text, nullable=True)
+    reminder_at = Column(DateTime, nullable=False, index=True)
+    status = Column(Enum(ReminderStatus), default=ReminderStatus.PENDING, nullable=False)
+    is_dismissed = Column(Boolean, default=False, nullable=False)