feat(D.2b): VitalsController — bind live vitals data by element id

Mirrors retail gmVitalsUI::PostInit: grab Health/Stamina/Mana meters from
the imported layout by their dat element ids (0x100000E6 / EC / EE) and
wire Func<float> fill + Func<string> label providers. Missing ids are
silently skipped (no throw). Slice sprites + dat font already set by the
factory — this is pure data wiring, not graphics.

3 TDD tests: single-meter fill+label, all-three distinct providers, missing-id no-throw.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/AcDream.App/UI/Layout/VitalsController.cs

@@ -0,0 +1,64 @@
+using System;
+
+namespace AcDream.App.UI.Layout;
+
+/// <summary>
+/// Per-window controller for the vitals layout (LayoutDesc 0x2100006C).
+/// Mirrors retail <c>gmVitalsUI::PostInit</c>: grab the three meter elements
+/// by their dat element ids and bind live data providers (fill fraction + cur/max
+/// text) to each. This is the ONLY per-window code in the whole importer — pure
+/// data wiring, not graphics.
+///
+/// <para>The slice sprites + dat font on each <see cref="UiMeter"/> are already
+/// set by <see cref="DatWidgetFactory"/> during tree construction; this controller
+/// only binds the dynamic vitals data. Do not touch meter rendering fields here.</para>
+/// </summary>
+public static class VitalsController
+{
+    /// <summary>Dat element id for the Health meter (0x100000E6).</summary>
+    public const uint Health  = 0x100000E6;
+    /// <summary>Dat element id for the Stamina meter (0x100000EC).</summary>
+    public const uint Stamina = 0x100000EC;
+    /// <summary>Dat element id for the Mana meter (0x100000EE).</summary>
+    public const uint Mana    = 0x100000EE;
+
+    /// <summary>
+    /// Bind live vitals data providers to the Health, Stamina, and Mana meter
+    /// elements found in <paramref name="layout"/>. Any meter whose id is absent
+    /// from the layout is silently skipped — partial layouts (e.g. test fakes)
+    /// do not cause errors.
+    /// </summary>
+    /// <param name="layout">Imported vitals layout tree.</param>
+    /// <param name="healthPct">Provider returning Health fill fraction [0..1].</param>
+    /// <param name="staminaPct">Provider returning Stamina fill fraction [0..1].</param>
+    /// <param name="manaPct">Provider returning Mana fill fraction [0..1].</param>
+    /// <param name="healthText">Provider returning Health "cur/max" overlay text.</param>
+    /// <param name="staminaText">Provider returning Stamina "cur/max" overlay text.</param>
+    /// <param name="manaText">Provider returning Mana "cur/max" overlay text.</param>
+    public static void Bind(
+        ImportedLayout layout,
+        Func<float>  healthPct,
+        Func<float>  staminaPct,
+        Func<float>  manaPct,
+        Func<string> healthText,
+        Func<string> staminaText,
+        Func<string> manaText)
+    {
+        BindMeter(layout, Health,  healthPct,  healthText);
+        BindMeter(layout, Stamina, staminaPct, staminaText);
+        BindMeter(layout, Mana,    manaPct,    manaText);
+    }
+
+    private static void BindMeter(
+        ImportedLayout layout, uint id,
+        Func<float>  pct,
+        Func<string> text)
+    {
+        if (layout.FindElement(id) is UiMeter m)
+        {
+            m.Fill  = () => pct();
+            m.Label = () => text();
+        }
+        // Silently skip if the id is absent — missing meters are not an error.
+    }
+}