Fix text issue (#12221)

### What problem does this PR solve?

Fix several text issues.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

api/db/db_models.py

@@ -1189,7 +1189,7 @@ class Memory(DataBaseModel):
     permissions = CharField(max_length=16, null=False, index=True, help_text="me|team", default="me")
     description = TextField(null=True, help_text="description")
     memory_size = IntegerField(default=5242880, null=False, index=False)
-    forgetting_policy = CharField(max_length=32, null=False, default="fifo", index=False, help_text="lru|fifo")
+    forgetting_policy = CharField(max_length=32, null=False, default="FIFO", index=False, help_text="LRU|FIFO")
     temperature = FloatField(default=0.5, index=False)
     system_prompt = TextField(null=True, help_text="system prompt", index=False)
     user_prompt = TextField(null=True, help_text="user prompt", index=False)

api/db/joint_services/memory_message_service.py

@@ -96,7 +96,7 @@ async def save_to_memory(memory_id: str, message_dict: dict):
     current_memory_size = get_memory_size_cache(memory_id, tenant_id)
     if new_msg_size + current_memory_size > memory.memory_size:
         size_to_delete = current_memory_size + new_msg_size - memory.memory_size
-        if memory.forgetting_policy == "fifo":
+        if memory.forgetting_policy == "FIFO":
             message_ids_to_delete, delete_size = MessageService.pick_messages_to_delete_by_fifo(memory_id, tenant_id, size_to_delete)
             MessageService.delete_message({"message_id": message_ids_to_delete}, tenant_id, memory_id)
             decrease_memory_size_cache(memory_id, delete_size)