fix: make frontend build and app deploy

[aymenfurter]

Motivation and Context

Fix the deployment issues when using the AZD command.

Description

This PR addresses the following issues:

• Build Failures: The deployment through AZD fails due to out-of-memory (OOM).
• Post-Provision Hooks: The post-provision hooks fail because the embedding endpoint is incorrectly configured.
• App Service Startup: The app service doesn't start due to a missing startup command.
• Incorrect Configuration: The app is incorrectly configured and doesn't perform Retrieval-Augmented Generation (RAG) because DATASOURCE_TYPE is not set.

Contribution Checklist

• I have built and tested the code locally and in a deployed app. (only posix)