refactor(drivers): organize backup modules into drivers subfolder

- Move all backup_*.py files to libtisbackup/drivers/ subdirectory
- Move XenAPI.py and copy_vm_xcp.py to drivers/ (driver-specific)
- Create drivers/__init__.py with automatic driver imports
- Update tisbackup.py imports to use new structure
- Add pyvmomi>=8.0.0 as mandatory dependency
- Sync requirements.txt with pyproject.toml dependencies
- Add pylint>=3.0.0 and pytest-cov>=6.0.0 to dev dependencies
- Configure pylint and coverage tools in pyproject.toml
- Add conventional commits guidelines to CLAUDE.md
- Enhance .gitignore with comprehensive patterns for Python, IDEs, testing, and secrets
- Update CLAUDE.md documentation with new structure and tooling

Breaking Changes:
- Drivers must now be imported from libtisbackup.drivers instead of libtisbackup
- All backup driver files relocated to drivers/ subdirectory

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

pyproject.toml

@@ -10,9 +10,10 @@ dependencies = [
     "flask-login>=0.6.0",
     "huey==2.5.3",
     "iniparse==0.5",
-    "paramiko==3.5.1",
+    "paramiko==4.0.0",
     "peewee==3.17.9",
     "pexpect==4.9.0",
+    "pyvmomi>=8.0.0",
     "redis==5.2.1",
     "requests==2.32.3",
     "ruff>=0.13.3",
@@ -43,3 +44,99 @@ indent-width = 4
 
 [tool.ruff.lint]
 ignore = ["F401", "F403", "F405", "E402", "E701", "E722", "E741"]
+
+[tool.pytest.ini_options]
+# Pytest configuration for TISBackup
+
+# Test discovery patterns
+python_files = ["test_*.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+
+# Test paths
+testpaths = ["tests"]
+
+# Output options
+addopts = [
+    "-v",
+    "--strict-markers",
+    "--tb=short",
+    "--color=yes",
+]
+
+# Markers for categorizing tests
+markers = [
+    "unit: Unit tests for individual functions/methods",
+    "integration: Integration tests that test multiple components together",
+    "ssh: Tests related to SSH functionality",
+    "slow: Tests that take a long time to run",
+]
+
+# Minimum Python version
+minversion = "3.13"
+
+# Coverage options (optional - uncomment when pytest-cov is installed)
+# addopts = ["--cov=libtisbackup", "--cov-report=html", "--cov-report=term-missing"]
+
+[tool.pylint.main]
+# Maximum line length
+max-line-length = 140
+
+# Files or directories to skip
+ignore = ["tests", ".venv", "__pycache__", ".pytest_cache", "build", "dist"]
+
+[tool.pylint."messages control"]
+# Disable specific warnings to align with ruff configuration
+disable = [
+    "C0103",  # invalid-name (similar to ruff E741)
+    "C0114",  # missing-module-docstring
+    "C0115",  # missing-class-docstring
+    "C0116",  # missing-function-docstring
+    "R0902",  # too-many-instance-attributes
+    "R0903",  # too-few-public-methods
+    "R0913",  # too-many-arguments
+    "R0914",  # too-many-locals
+    "W0703",  # broad-except (similar to ruff E722)
+    "W0719",  # broad-exception-raised
+]
+
+[tool.pylint.format]
+# Indentation settings
+indent-string = "    "
+
+[tool.coverage.run]
+# Source code to measure coverage for
+source = ["libtisbackup"]
+
+# Omit certain files
+omit = [
+    "*/tests/*",
+    "*/__pycache__/*",
+    "*/site-packages/*",
+    "*/.venv/*",
+]
+
+[tool.coverage.report]
+# Precision for coverage percentage
+precision = 2
+
+# Show lines that weren't covered
+show_missing = true
+
+# Skip files with no executable code
+skip_empty = true
+
+# Fail if coverage is below this percentage
+# fail_under = 80
+
+[tool.coverage.html]
+# Directory for HTML coverage report
+directory = "htmlcov"
+
+[dependency-groups]
+dev = [
+    "pylint>=3.0.0",
+    "pytest>=8.4.2",
+    "pytest-cov>=6.0.0",
+    "pytest-mock>=3.15.1",
+]