feat(agent): add redis short-term user context cache and align tests

backend/src/models/schedule_items.py

@@ -5,10 +5,11 @@ from datetime import datetime
 from enum import Enum
 
 from sqlalchemy import DateTime, String, Text
-from sqlalchemy.dialects.postgresql import JSONB, UUID
+from sqlalchemy.dialects.postgresql import UUID
 from sqlalchemy.orm import Mapped, mapped_column
 
 from core.db.base import Base, SoftDeleteMixin, TimestampMixin
+from core.db.types import json_jsonb
 
 
 class ScheduleItemStatus(str, Enum):
@@ -58,7 +59,7 @@ class ScheduleItem(TimestampMixin, SoftDeleteMixin, Base):
     )
     extra_metadata: Mapped[dict] = mapped_column(
         "metadata",
-        JSONB,
+        json_jsonb,
         nullable=False,
         server_default="{}",
     )