v0.2.6: Overhaul UI/UX, desktop environment, and agent features

Desktop:
- Upgrade to XFCE4 desktop with Arc-Dark theme, Papirus icons, and
  proper xfce4-panel (applications menu, taskbar, systray, clock)
- Fix xfwm4 window decorations (remove invalid --daemon flag, start
  dbus session for xfconf settings to load)
- Change resolution from 1280x720 to 1280x768
- Maximize Firefox on launch via xfwm4 alt+F10 shortcut
- Replace inline printf configs with COPY of proper XML/ini files

Dashboard:
- Add permanent non-closable Home tab with WelcomeGuide always accessible
- Sessions never replaced by landing page, state preserved on disconnect
- Add password field to manual Connect a Desktop config
- Add CLI configurator with OS/persist/open options and dynamic command
- Fix npx command to use @latest everywhere
- Restructure preset goal buttons with flex-wrap layout
- Add configurable max steps (1-200) to WorkflowPanel
- Track and display LLM token usage (input/output) in running indicator
- Replace emoji icons with SVG icons in ActivityFeed
- Show bash commands in activity feed
- Rename iterations to steps throughout
- Fix overlay Y-axis mismatch (720 -> 768)

Example apps:
- Replace native <select> with custom div-based dropdowns in all three
  forms for reliable xdotool interaction

Auth:
- Add bearer token auth support for manually configured sessions