fix: 完善 UT 覆盖，统一 pytest 测试发现 - Closes #2

- 新建 pytest.ini 统一 test discovery（tests/ + skills/ir_generation_skill/tests/）
- test_step1~3 转换为 pytest 兼容格式，无输出文件时自动 skip
- 新增 tests/test_detect_conflicts.py（18 个纯函数单测）
- 新增 tests/test_config.py（7 个配置模块单测）
- CI 改为 pytest -v 使用 pytest.ini testpaths
- DEV_AGENT.md 新增 PR 提交规范

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

skills/ir_generation_skill/tests/test_step2_5.py

@@ -147,6 +147,32 @@ def run_all_tests():
     return total_failures == 0
 
 
+# ═══════════════════════════════════════════════════════════════════════════════
+# pytest discovery support
+# ═══════════════════════════════════════════════════════════════════════════════
+
+import pytest  # noqa: E402
+
+
+def test_step2_5_path_enumeration():
+    """pytest: path_enumeration.json should have valid structure."""
+    try:
+        path_data = config.load_json(config.PATH_ENUM_JSON)
+    except FileNotFoundError:
+        pytest.skip("path_enumeration.json not found — run step2_5_branch_coverage.py first")
+    errors = check_path_enumeration(path_data)
+    assert not errors, f"path enumeration errors: {errors}"
+
+
+def test_step2_5_autocomplete_fragments():
+    """pytest: auto-complete fragments must have valid structure if present."""
+    fragments = load_autocomplete_fragments()
+    errors = check_autocomplete_fragments(fragments)
+    # If fragments is None (no autocomplete needed), check_autocomplete_fragments returns a warning
+    actual_errors = [e for e in errors if "未生成" not in e]
+    assert not actual_errors, f"autocomplete fragment errors: {actual_errors}"
+
+
 if __name__ == "__main__":
     success = run_all_tests()
     sys.exit(0 if success else 1)