🔨 improve CI/CD and code quality

[Miyamura80]

Summary

• Expand ruff rules with B (bugbear), C4 (comprehensions), SIM (simplify) and fix all resulting violations (B904, B028, B009, C416, SIM114)
• Extract _identify_provider() helper in global_config.py to deduplicate model-name regex matching across llm_api_key() and api_base()
• Narrow exception catches in dspy_inference.py and dspy_langfuse.py to specific exception types
• Add thread-safe logging initialization with threading.Lock() and double-checked locking pattern
• Fix Python version in ruff workflow to dynamically read from .python-version file
• Add ruff-check hook to .pre-commit-config.yaml
• Enable pytest coverage collection with --cov=src --cov=common --cov=utils (was previously a no-op without --cov)
• Remove utils/llm/** from coverage omit so LLM utilities are measured

Test plan

• make ruff passes with expanded rules
• make fmt produces no formatting changes
• make test_fast — all 4 tests pass including new thread-safety test
• Coverage properly collected and reported (23% with fast tests, threshold set to 20%)
• Pre-commit hooks pass (large files, fmt, ruff)

🤖 Generated with Claude Code

[greptile-apps]

Greptile Overview

Greptile Summary

This PR systematically improves code quality and CI/CD infrastructure. Expands ruff linting with bugbear (B), comprehensions (C4), and simplify (SIM) rules and fixes all resulting violations including proper exception chaining (B904), narrowing bare exception catches, and simplifying dict/isinstance usage. Extracts _identify_provider() helper in common/global_config.py to eliminate duplicated provider detection logic. Adds thread-safe logging initialization using double-checked locking pattern with comprehensive test coverage. Improves CI/CD by splitting test targets (fast/slow/nondeterministic), dynamically reading Python version from .python-version file, and adding pre-commit ruff checks. Enables pytest coverage collection that was previously a no-op and measures LLM utility coverage.

• Thread-safe logging with threading.Lock() and double-checked locking pattern in src/utils/logging_config.py:148-150
• New _identify_provider() helper deduplicates model name regex matching in common/global_config.py:226-239
• Exception chaining with from e added to all caught exceptions (B904)
• Narrowed exception catches from bare Exception to specific types in utils/llm/dspy_inference.py:80 and utils/llm/dspy_langfuse.py:232
• Coverage now properly collected with --cov=src --cov=common --cov=utils in pytest.ini:6
• Test targets split into test_fast, test_slow, test_nondeterministic for better CI organization

Confidence Score: 5/5

• Safe to merge with high confidence - all changes are code quality improvements with proper test coverage
• All changes improve code quality through linting fixes, proper exception handling, thread safety, and better test organization. The thread-safety implementation uses standard double-checked locking pattern with comprehensive test coverage. Exception handling improvements follow best practices. CI/CD enhancements are well-structured.
• No files require special attention

Important Files Changed

Filename	Overview
common/global_config.py	Added _identify_provider() helper to deduplicate provider detection, added from e to exception chains (B904), added stacklevel=2 to warnings.warn (B028)
pyproject.toml	Expanded ruff rules with B (bugbear), C4 (comprehensions), SIM (simplify), removed utils/llm/** from coverage omit
pytest.ini	Added coverage collection with --cov=src --cov=common --cov=utils, lowered threshold to 20%
src/utils/logging_config.py	Added thread-safe logging initialization with threading.Lock() and double-checked locking pattern
tests/test_logging_thread_safety.py	New test verifying concurrent setup_logging() calls only initialize logging once
utils/llm/dspy_inference.py	Narrowed exception catch from bare Exception to specific types (RuntimeError, ValueError, TypeError)
utils/llm/dspy_langfuse.py	Replaced dict comprehension with dict() call (C416), narrowed exception catches, simplified isinstance check with tuple (SIM114)