Add coverage reporting to CI test workflow

[Miyamura80]

Summary

• Add --cov flags to pytest in CI to report code coverage
• Covers src/, common/, and utils/ directories
• Uses existing pytest-cov dependency and [tool.coverage] config in pyproject.toml

Test plan

• CI workflow runs successfully
• Coverage report appears in test output

🤖 Generated with Claude Code

[greptile-apps]

Greptile Overview

Greptile Summary

This PR adds coverage reporting to the CI test workflow by enabling pytest-cov flags when running fast tests. The implementation correctly uses the existing pytest-cov dependency and aligns with the [tool.coverage] configuration already defined in pyproject.toml.

• Added --cov=src --cov=common --cov=utils flags to track coverage across the three main source directories
• Added --cov-report=term-missing to show which lines are not covered in the CI output
• Updated step name from "Run fast tests" to "Run fast tests with coverage" for clarity

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The change is a simple, well-scoped addition that adds coverage reporting flags to an existing pytest command. The implementation correctly leverages the existing pytest-cov dependency (v7.0.0+) and aligns perfectly with the coverage configuration already defined in pyproject.toml. The change is purely additive to CI observability and does not modify any production code or test behavior.
• No files require special attention

Important Files Changed

Filename	Overview
.github/workflows/a_test_target_tests.yml	Added coverage reporting flags to pytest command, leveraging existing pytest-cov dependency and coverage config