Tests: Add API tests for new Model endpoints

[akshajtiwari]

Description

Adds test coverage for the newly introduced Model APIs.

Endpoints to cover

Method	Endpoint
GET	/models/status
GET	/models/hardware
POST	/models/setup
POST	/models/download/{model_name}
GET	/models/download/{task_id}/progress
DELETE	/models/{model_name}

Tasks

• Write happy path + edge case tests for each endpoint

[github-actions]

👋 Thanks for opening this issue! The maintainers will review it shortly. Till then, do not open any PR. This is a strict rule we like to follow around here :)

[akshajtiwari]

@rohan-pandeyy Kindly assign this issue to me