AutoSign 0.18.3

Highlights\n\n- Added a dedicated calendar-and-check favicon for the Web UI.\n- Improved Baidu Tieba batch sign-in safety: fixed pacing, detection of CAPTCHA/login/rate-limit signals, and a safe stop for unattempted forums.\n- Updated execution details and notifications for interaction-required outcomes.\n\n## Verification\n\n- Full Python test suite: 250 passed.\n- Ruff check for product source and tests passed.\n- linux/amd64 image build and isolated container smoke test passed.\n\n## Notes\n\nThis release does not include private NAS deployment artifacts, configuration, keys, account data, or backups.