fix(email): support implicit SSL (port 465) for SMTP test; add use_ssl field + encryption selector

backend/python/app/models.py

@@ -84,6 +84,7 @@ class Conversation(Base):
     status = Column(String(10), nullable=False, default="active")  # active / archived
     pinned = Column(Boolean, default=False)
     knowledge_graph_count = Column(Integer, default=0)
+    knowledge_graph_base_id = Column(String(64), default=None, comment="已生成的知识图谱知识库ID")
     created_at = Column(DateTime, default=datetime.now)
     updated_at = Column(DateTime, default=datetime.now, onupdate=datetime.now)
 
@@ -626,6 +627,7 @@ class EmailConfig(Base):
     password = Column(String(200), nullable=False)
     from_address = Column(String(200), nullable=False)
     use_tls = Column(Boolean, default=True)
+    use_ssl = Column(Boolean, default=False)
     created_at = Column(DateTime, default=datetime.now)
     updated_at = Column(DateTime, default=datetime.now, onupdate=datetime.now)