v1.1.0

Add Settings dialog for Anthropic API key management

- config.py: read/write ~/.worklog/config.json for persistent settings
- ui/settings_dialog.py: masked key entry with show/hide toggle, live
  status indicator, saves key to config and applies to os.environ immediately
- topbar: ⚙ Settings button opens the dialog
- main.py: loads stored API key from config on startup
- ai_summary.py: error message now points to Settings instead of env var

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

v1.0.0

Add cross-platform build pipeline via PyInstaller and GitHub Actions

- worklog.spec: PyInstaller config bundling customtkinter data files,
  produces onedir build on Linux/Windows and .app bundle on macOS
- .github/workflows/build.yml: builds on ubuntu/windows/macos-latest,
  packages as tar.gz / zip / zip, attaches to GitHub Release on tag push
- README: add Download section with per-platform install instructions

Trigger a release by pushing a version tag: git tag v1.0.0 && git push --tags

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>