Window management on top of the engine: full-screen, swapping pane positions and types, drag-to-resize tiles, session auto-save, and the first Workspace Trust gate. Everything in this chain shipped.

v0.2.0 - UI/UX

Done	Area	Item
✅	BUILD	Standalone export - first CI release producing self-contained binaries for Linux, macOS, and Windows. No Godot editor or Rust toolchain required to run - just download and launch.
✅	GUI	Full-screen mode - three window modes: OS-decorated, borderless, and fullscreen. Custom-drawn titlebar with minimize, maximize/restore, and close buttons. Toggle via sidebar or keyboard shortcut.
✅	GUI	Pane position and type swapping - swap panes between grid positions or change a pane’s type (terminal ↔ code viewer) via sidebar buttons and popup menus.
✅	GUI	Drag-to-resize tile edges - drag the splitter handles between panes to resize grid columns and rows. Built on Godot HSplitContainer/VSplitContainer with a Rust tile layout engine enforcing minimum sizes.
✅	GUI	Session auto-save - layout and pane state persist across application restarts. PTY sessions are recreated with fresh shells on relaunch (process state and scrollback are not restored - see the v0.4.0 SQLite history item).
✅	SEC	Workspace Trust - layouts loaded from external sources show a confirmation dialog before spawning PTY processes. Prevents malicious layout files from executing arbitrary commands.