[Bug]: several api bugs

[zydmtaichi]

Is there an existing issue for the same bug?

• I have checked the existing issues.

RAGFlow workspace code commit ID

1d0a560

RAGFlow image version

dev

Other environment information

os type: ubuntu 22.04

Actual behavior

1.the api path should /v1/api while the path that doc describes starts with /api/v1
2.the api in code like api_app.py is /completion while the api in doc is /completions
3.the agent api is invalid (like /api/v1/agents/{agent_id}/completions)

Expected behavior

No response

Steps to reproduce

1.refer [doc](https://ragflow.io/docs/dev/http_api_reference) and the api define code like `api_app.py`
2.use postman to send the post request to `/api/v1/agents/{agent_id}/completions` api

Additional information

No response