feat: 重构 memory 系统，支持 user memory 和 work memory 分离

backend/src/models/automation_jobs.py

@@ -32,6 +32,10 @@ class AutomationJob(TimestampMixin, SoftDeleteMixin, Base):
         UUID(as_uuid=True),
         nullable=False,
     )
+    bootstrap_key: Mapped[str | None] = mapped_column(
+        String(64),
+        nullable=True,
+    )
     title: Mapped[str] = mapped_column(
         String(255),
         nullable=False,

backend/src/models/memories.py

@@ -16,12 +16,6 @@ class MemoryType(str, Enum):
     WORK = "work"
 
 
-class MemorySource(str, Enum):
-    MANUAL = "manual"
-    AGENT = "agent"
-    IMPORTED = "imported"
-
-
 class MemoryStatus(str, Enum):
     ACTIVE = "active"
     DISABLED = "disabled"
@@ -46,15 +40,10 @@ class Memory(TimestampMixin, Base):
         String(20),
         nullable=False,
     )
-    title: Mapped[str | None] = mapped_column(String(255), nullable=True)
     content: Mapped[dict] = mapped_column(
         json_jsonb,
         nullable=False,
     )
-    source: Mapped[MemorySource] = mapped_column(
-        String(20),
-        nullable=False,
-    )
     status: Mapped[MemoryStatus] = mapped_column(
         String(20),
         nullable=False,