v0.2.0

WTF v0.2.0

Spatial navigation, pluggable seams, Liquid Glass, and in-process surfaces —
plus a broad correctness/hardening pass.

Features since v0.1.2:
- Spatial foundation: directional focus + SwapWith / SwapDir.
- #9 COSMIC-style modal keyboard swap mode (highlight + commit).
- #10 Mouse drag to rearrange tiled windows (swap on drop).
- #5 Pluggable workspace TYPES (arranger seam, IWtfWorkspacePlugin).
- #6 Pluggable effect strategies (IWtfEffectPlugin).
- #7 Liquid Glass: index-scaled rim refraction (Part 1) + the advanced GLSL
  rim shader — chromatic aberration / noise / specular / surface (Part 2).
- Surfaces: status bar rendered in-process as a WM surface (embedded by
  default), in-process omnibox overlay, user surface plugins, custom + script
  bar widgets.
- Config: keybinding helpers, ricing toggles, full-keysym binding; run-or-raise
  across workspaces.

Correctness & hardening:
- Undo/redo no longer rewinds the live window set (orphan/ghost fix) or the
  C-side fullscreen flag; a folded map is pinned to its real workspace.
- Glass style setters refresh dependent decoration nodes (shadow z-order under
  glass, corner-radius clip/shadow/glow); shadow toggle re-arranges for z-order.
- Plugin-return boundaries hardened: null-return coalescing, per-facet
  registration isolation, sane unknown-layout fallback.