fix #394 #395 #396: OP8 re-gate round — caption font, retail key names, capture dialog

Three findings from the user's first Configure Keyboard look (OP8 gate,
2026-08-14), each root-caused against the named retail decomp:

- #394 row-caption font: the synthesized action-label UiText never set
  DatFont and fell to the debug bitmap font. The authored row template
  (0x21000009/0x1000002F, retail UIOption_ActionKeyMap) carries FontDid
  0x4000000A (18px serif) — Bind now takes resolveTemplateFont and applies
  the template's own authored font, resolved once per template pair.

- #395 key captions: raw enum spellings ("Shift+ShiftLeft") replaced by the
  port of CInputManager_WIN32::GetNameFromKey @0x00687F40 /
  GetNameFromKey_Internal @0x00687800 (RetailKeyNames): DAT string-table
  override by DIK-name hash (key enum 4 -> 0x2300000A, meta enum 5 ->
  0x2300000B, delimiter enum 3 -> 0x23000007 — GetDIDByEnum category 4,
  live-probed), else the OS keyboard layout's own key name ("SKIFT") via
  PlatformKeyNameProvider (Win32 GetKeyNameTextW — register row AD-96 for
  the DirectInput-vs-GetKeyNameText adaptation), else the DIK-suffix
  spelling. Bare modifier-key bindings show only the key name.

- #396 capture feedback: clicking a mapping button now opens retail's
  instruction dialog (InitiateBinding @0x004899D0 -> OpenMapWarnDialog
  @0x00488A00): a type-2 WAIT dialog on retail's MapWarn queue key
  0x10000001 with ID_ActionKeyMap_MapInstructions (0x23000004, ACTION
  variable interpolated), closed on key hit or ESC through the capture
  callback; capture is not armed if the dialog cannot open, matching
  retail. New RetailWaitDialogView (wait root 0x31 — same authored
  popup/message pair 0x3D/0x3E as the confirmation root, live-DAT probed)
  behind a shared IRetailDialogView presenter seam.

Probe evidence (env-gated, kept):
KeyboardConfigLiveMountProbeTests.ProbeKeyboardFontsAndKeyNameStrings.
Register: AD-96 filed. Gate script OP8 section updated (step 4 rewritten;
the "pressed/active state is enough" contract is retired).

Full Release solution suite green (13,424 passed / 4 skips).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/Platform/PlatformKeyNameProvider.cs

@@ -0,0 +1,43 @@
+using System.Runtime.InteropServices;
+
+namespace AcDream.App.Platform;
+
+/// <summary>
+/// Platform owner (L0 boundary — OS checks live under <c>Platform/</c> only)
+/// for the OS-localized key-name half of retail's
+/// <c>CInputManager_WIN32::GetNameFromKey_Internal @ 0x00687800</c> fallback:
+/// when the DAT string tables have no authored name for a key, retail shows
+/// the keyboard layout's own name ("SKIFT" on Swedish) via DirectInput's
+/// <c>IDirectInputDevice8::GetObjectInfo</c>. This port asks Win32
+/// <c>GetKeyNameTextW</c> instead — the same layout-resident name data, no
+/// DirectInput device needed (register row AD-96). Non-Windows hosts get no
+/// OS lookup (null) and callers fall back to the DIK-suffix spelling.
+/// </summary>
+public static class PlatformKeyNameProvider
+{
+    /// <summary>(scanCode, isExtended) → localized key name, or null when the
+    /// current platform has no OS lookup.</summary>
+    public static Func<byte, bool, string?>? ForCurrentProcess()
+        => OperatingSystem.IsWindows() ? WindowsKeyName : null;
+
+    /// <summary>
+    /// GetKeyNameTextW's lParam wants the hardware scan code in bits 16-23
+    /// and the extended-key flag in bit 24 — the same split DirectInput's
+    /// DIK codes carry in bit 0x80.
+    /// </summary>
+    private static string? WindowsKeyName(byte scan, bool extended)
+    {
+        Span<char> buffer = stackalloc char[64];
+        int lParam = (scan << 16) | (extended ? 1 << 24 : 0);
+        int length;
+        unsafe
+        {
+            fixed (char* p = buffer)
+                length = GetKeyNameTextW(lParam, p, buffer.Length);
+        }
+        return length > 0 ? new string(buffer[..length]) : null;
+    }
+
+    [DllImport("user32.dll", CharSet = CharSet.Unicode, ExactSpelling = true)]
+    private static extern unsafe int GetKeyNameTextW(int lParam, char* lpString, int cchSize);
+}