v0.1.0

First preview release.

Public API

• Retained widget tree with generational handles and subtree removal.
• 30 widget kinds: container, spacer, text, button, checkbox, radio
  button, tree item, dropdown, popup, tooltip, menu bar / menu / menu
  item, list box, selectable, grid selector, grid item, table / row /
  cell, toolbar, status bar, drag value, spinbox, slider, text input,
  tab bar / tab item, splitter, scroll area.
• Context (single-tree convenience) and Runtime (multi-tree
  primitive) with thin-forward symmetry. WidgetDesc for construction,
  NodeView / WidgetView for reads, mutateKind / setStyle /
  updateWidget / setCustomDraw for writes.
• Per-kind internal substructs hide dispatch/draw-owned per-frame
  state (drag rects, marquee, editor buffers) from embedders.
• Platform-neutral Event model (mouse, key, text, focus, resize)
  with a Modifiers bitmask carried on key/mouse events.
• DrawCommand output (rect, text, clip, icon, custom)
  consumed by an embedder-owned renderer. PaintCommand for embedders
  that want the higher-level pre-render representation.
• Per-widget style overrides via Style (resolved against Theme).
• Optional TextMeasureCtx injection for accurate text sizing.
• Optional Clipboard callback interface for cut/copy/paste in text
  inputs.
• C API in include/goop.h mirroring the Zig surface; libgoop
  ships as both static archive and shared library.

Reference embedders

• Wayland / EGL / OpenGL demo (zig build demo).
• File-manager demo backed by the real filesystem (zig build file-manager-demo).
• Headless rendering pipeline used for CI screenshot regression
  (zig build screenshot).
• Headless C API example (zig build c-example).

Known limitations

• Text editing is codepoint-aware UTF-8 but not grapheme-cluster-aware;
  IME composition is not implemented.
• MSAA sample count is hardcoded to 4× with no capability fallback.
• The public API may still shift between minor versions until 1.0.