Feature: Add CI workflow for linting, testing, and security scanning

[duartebarbosadev]

This pull request introduces significant improvements to the project's CI/CD pipeline, test coverage enforcement, and unit testing for the image rotation detection feature. The most important changes are the addition of a comprehensive GitHub Actions workflow for CI, basic security scanning, and PR summaries; enforcement of a minimal coverage threshold; and new, focused unit tests for the rotation detector. These changes collectively enhance code quality, reliability, and maintainability.

CI/CD and Quality Enforcement

• Added a new .github/workflows/ci.yml GitHub Actions workflow that runs linting, testing (with coverage), basic security scanning, and generates PR summaries. This workflow includes scheduled weekly runs and concurrency control to prevent overlapping CI jobs.
• Introduced a minimal coverage threshold for tests via pytest.ini, ensuring that builds fail if coverage drops below 8%. This sets a baseline for gradually increasing coverage.
• Updated requirements-dev.txt to explicitly list testing and linting tools (pytest, pytest-cov, ruff), improving clarity and reproducibility of the development environment.

Testing Enhancements

• Added a new unit test suite (tests/test_model_rotation_detector_unit.py) for the ModelRotationDetector, covering lazy initialization, prediction logic when the model is missing, stubbed session behavior, and disabled mode handling. This improves the reliability and testability of the image rotation detection feature.

Documentation

• Updated the developer guide (DEVELOPER_GUIDE.md) to include a new section on adding image feature pipelines, supporting future extensibility and onboarding.

These changes collectively improve the project's CI reliability, code quality enforcement, and test coverage.

[Copilot]

Pull Request Overview

This PR introduces a comprehensive CI/CD pipeline with GitHub Actions, enforces basic test coverage requirements, and restructures the test suite for better organization and reliability. The changes include adding automated workflows for linting, testing, and security scanning, while removing problematic GUI-heavy tests in favor of focused unit tests.

• Adds a complete GitHub Actions CI workflow with linting, testing, coverage enforcement, and basic security scanning
• Introduces test coverage enforcement with an 8% minimum threshold via pytest configuration
• Replaces unstable GUI integration tests with focused unit tests for the ModelRotationDetector
• Removes empty package __init__.py files and improves import handling for optional dependencies

Reviewed Changes

Copilot reviewed 13 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
.github/workflows/ci.yml	Comprehensive CI workflow with lint, test, security scan, and PR summary jobs
pytest.ini	Coverage threshold configuration enforcing 8% minimum
requirements-dev.txt	Development dependencies including pytest, pytest-cov, and ruff
tests/test_model_rotation_detector_unit.py	New focused unit tests for ModelRotationDetector
tests/test_rotation_accept_unit.py	Removed unstable GUI-dependent tests
tests/test_rotation_accept_integration.py	Removed integration tests dependent on sample folder
src/core/image_pipeline.py	Improved optional import handling for PIL.ImageQt
Various __init__.py files	Removed empty package initialization files
DEVELOPER_GUIDE.md	Minor formatting addition