feat: Update model endpoints + skeleton for model labels

[itallix]

Summary

This PR updates the existing model endpoints to include the project ID. Additionally, it introduces a skeleton for the model labels snapshot endpoint.

Note:
This PR should be merged after #4672 and the base branch should be updated to develop before merging.

How to test

1. Run the server with ./run.sh
2. The following APIs should work:

# Get available model revisions from the project
curl localhost:7860/api/projects/9d6af8e8-6017-4ebe-9126-33aae739c5fa/models
# Get details about project model revision
curl localhost:7860/api/projects/9d6af8e8-6017-4ebe-9126-33aae739c5fa/models/977eeb18-eaac-449d-bc80-e340fbe052ad
# Delete model revision
curl -X DELETE localhost:7860/api/projects/9d6af8e8-6017-4ebe-9126-33aae739c5fa/models/977eeb18-eaac-449d-bc80-e340fbe052ad

Checklist

• I have added unit tests to cover my changes.​
• I have added integration tests to cover my changes.​
• I have ran e2e tests and there is no issues.
• I have added the description of my changes into CHANGELOG in my target branch (e.g., CHANGELOG in develop).​
• I have updated the documentation in my target branch accordingly (e.g., documentation in develop).
• I have linked related issues.

License

• I submit my code changes under the same Apache License that covers the project.
  Feel free to contact the maintainers if that's a concern.
• I have updated the license header for each file (see an example below).

# Copyright (C) 2025 Intel Corporation
# SPDX-License-Identifier: Apache-2.0

[Copilot]

Pull Request Overview

This PR updates the model endpoints to include project ID as a required parameter and introduces a skeleton for a model labels endpoint. The changes refactor the model service to work within project contexts rather than globally.

• Updates all model endpoints to require project ID and validates project existence
• Adds a new skeleton endpoint for retrieving model labels
• Refactors model service methods to accept project ID parameter

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
backend/app/api/endpoints/models.py	Updates endpoints to include project ID in URLs and adds model labels skeleton endpoint
backend/app/services/model_service.py	Refactors service methods to accept project ID and validate project existence
backend/app/repositories/base.py	Adds exists() method for checking entity existence
backend/app/db/schema.py	Adds model_revisions relationship to ProjectDB
backend/app/repositories/label_repo.py	Changes constructor parameter order for consistency
backend/app/services/label_service.py	Updates LabelRepository instantiation to match new constructor
backend/tests/unit/endpoints/test_models.py	Updates tests to include project ID in API calls
backend/tests/integration/services/test_model_service.py	Updates integration tests for new service method signatures

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[github-actions]

Docker Image Sizes

Image	Size
geti-tune-pr-4744	1.1G
geti-tune-sha-c837c21	1.1G

[github-actions]

📊 Test coverage report

Metric	Coverage
Lines	27.9%
Functions	30.5%
Branches	85.8%
Statements	27.9%