Fix #245: Expanded configured log_file paths with os.path.expanduser()

[dbcli-symphony]

Summary

• Expanded configured log_file paths with os.path.expanduser() before directory creation/checking in litecli/main.py.
• Added a regression test for log_file = ~/.cache/litecli/log with a temporary home directory in tests/test_main.py.

Issue

Fixes #245

Verification

• python -m py_compile litecli/main.py tests/test_main.py passed.
• ruff check litecli/main.py tests/test_main.py passed.
• ruff format --check litecli/main.py tests/test_main.py passed.
• git diff --check passed.
• Could not run the focused pytest: pytest is not installed in the active Python. tox -e py also could not bootstrap because the sandbox has no network access to install uv. Remaining risk is only that the new pytest has not been executed in this environment.