v0.4.0

• Route commands and keybindings through one context-aware command registry.
• Register the explorer, project search, terminal, and plugin panels through one stateful panel registry.
• Supply Git gutter marks and selection highlights through the decoration registry.
• Include inline and block decorations in wrapping, display coordinates, hit testing, and generic rendering.
• Expose rendered panels, badges, and decorations through stable UI test identifiers.

Full Changelog: v0.3.0...v0.4.0