OpenCadAgentService initialized in 2 places

[isayahc]

Description

• OpenCadAgentService is initialized in backend/opencad/runtime.py and in backend/opencad_agent/api.py

Things that need to be done

• find out if this is causing any issues. Best scenario makes the code base harder to read. Worst case both are being used at once
• get rid of the one of these services

Further Analysis

• I am also noticing there is a chat method in the RuntimeContext as well as a chat method in OpenCadAgentService