Add user-configurable timezone and 12/24-hour preferences, then wire them through settings, runtime snapshots, scheduler payloads, wait handling, notifications, backups, memory, plugin metadata, and frontend formatters.
Keep UTC as the boundary for absolute instants while serializing user-facing dates in the configured or browser-resolved timezone. Preserve scheduler wall-clock inputs in the selected timezone, propagate TZ into desktop/runtime process environments, and restart active desktop sessions when the runtime timezone changes.
Cover the risky paths with timezone regression tests for settings normalization, auto and fixed timezone resolution, scheduler round-trips, memory timestamp conversion, and desktop timezone sync.
- Extract UI server setup into UiServerRuntime class with modular initialization
- Move environment configuration, route registration, and transport handlers to helpers/ui_server.py
- Add released_at timestamp tracking for git tags and branch heads across update system
- Implement get_current_major_main_latest_info to find latest same-major version on main branch
- Add major_upgrade_versions and main_branch_latest fields to update info payload
- Remove