Implements Task 8 of the D.2b retail-UI plan. MarkupDocument.Build() parses
KSML-style panel markup into a live UiNineSlicePanel subtree, resolving
{Binding} attribute expressions against a supplied object via reflection.
Color format is #AARRGGBB (alpha-first, matching controls.ini). Handles
<panel> root (geometry + optional title label) and <meter> children (fill,
label, bar color). Future element kinds (label, button, image) extend the
switch without touching existing code.
vitals.xml encodes the just-approved vitals panel layout (health red #FFC70D0D,
stamina gold #FFD49E1F, mana blue #FF1F33D9); ships next to the binary via
PreserveNewest csproj rule. GameWindow.cs drops the 35-line hand-built panel
block in favour of a 4-line File.ReadAllText + MarkupDocument.Build call —
identical tree, identical render, now data-driven.
2 new tests (Build_CreatesPanelWithMeterFillLabelAndGeometry,
Build_NullBindingValuesYieldNullFillAndLabel) + 11 total targeted green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
