Phase 7: cockpit overlay generator, region extraction, and profile editor

Overlay generator (pure, tested) — RioJoy.Core/Overlay:
- FontFitter ports the legacy calc-fontsize auto-fit search (validated against a
  brute-force oracle); OverlayLayoutEngine ports create-data-layer's fit + h/v
  justification and adds per-region 90 deg CCW rotation; OverlayTemplate/Region +
  OverlayTemplateStore hold cell geometry/colour/rotation (regions.json).
- GoobieDataImporter parses the legacy .data label sheet into label rows.
- src/RioJoy.Overlay: SkiaSharp rasterizer (SkiaTextMeasurer shared with the engine
  so measured layout == drawn output; SkiaOverlayRenderer -> PNG;
  ProfileWallpaperGenerator). Verified end-to-end on the real cockpit art
  (regions.json + riojoy.png + TEST.data) by OverlayRenderIntegrationTests.
- RioJoy.Tray/WallpaperApplier applies via SystemParametersInfo; RioCoordinator
  generates+applies on profile activation (opt-in via AppConfig.OverlayTemplatePath).

Region geometry — tools/XcfRegionExtract parses riojoy.xcf (a GIMP-format binary
reader, no GIMP needed) into the 119-cell regions.json: per-layer offsets/size/
font/colour, with 90 deg CCW rotation on a-00 + b-10..b-1F. Base image riojoy.png.
NOTE: the wallpaper positions are a VGA chroma-split display artifact (6 displays),
not the cockpit's logical layout.

Mapping editor (first cut) — RioJoy.Tray/Editor/ProfileEditorForm renders the
config sheet's logical grid (SheetLayout parses the sheet CSV export). The iRIO
word is edited via ButtonBinding <-> RioMapEntry.Create (no hex bit-twiddling), with
a context-sensitive picker: keyboard keys by name (KeyCatalog VK names), joystick
Button N, hat direction, mouse/RIO-command enum names; modifiers only for keyboard.
Opened from the tray ("Edit profile..."). The sheet-grid layout is a starting point
that needs rework from a better-formatted source.

~220 xUnit tests green. Docs (PLAN.md, README) updated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/RioJoy.Core.Tests/Overlay/OverlayRenderIntegrationTests.cs

@@ -0,0 +1,50 @@
+using RioJoy.Core.Overlay;
+using RioJoy.Overlay;
+using SkiaSharp;
+using Xunit;
+
+namespace RioJoy.Core.Tests.Overlay;
+
+/// <summary>
+/// Full Phase-7 pipeline on the real cockpit assets: extracted regions.json + the
+/// exported riojoy.png + the legacy TEST.data labels → a rendered wallpaper. Proves
+/// the extract → import → lay out → rasterize chain end to end (headless).
+/// </summary>
+public class OverlayRenderIntegrationTests
+{
+    private static bool RegionDiffers(SKBitmap a, SKBitmap b, OverlayRegion r)
+    {
+        int x0 = (int)r.X, y0 = (int)r.Y;
+        int x1 = Math.Min(a.Width, (int)(r.X + r.Width));
+        int y1 = Math.Min(a.Height, (int)(r.Y + r.Height));
+        for (int y = y0; y < y1; y++)
+        for (int x = x0; x < x1; x++)
+            if (a.GetPixel(x, y) != b.GetPixel(x, y))
+                return true;
+        return false;
+    }
+
+    [Fact]
+    public void RendersCockpitWallpaper_FromRealAssets()
+    {
+        OverlayTemplate template = OverlayTemplateStore.Load(TestRepo.CustomBackground("regions.json"));
+        Assert.False(string.IsNullOrWhiteSpace(template.BaseImagePath));
+
+        using SKBitmap baseImg = SKBitmap.Decode(TestRepo.CustomBackground(template.BaseImagePath!));
+        Assert.NotNull(baseImg);
+        Assert.Equal(template.Width, baseImg.Width);
+        Assert.Equal(template.Height, baseImg.Height);
+
+        IReadOnlyDictionary<string, string> labels =
+            GoobieDataImporter.LabelsForRow(GoobieDataImporter.Load(TestRepo.CustomBackground("TEST.data")));
+
+        using SKBitmap rendered = new SkiaOverlayRenderer().Render(template, labels, baseImg);
+
+        Assert.Equal(2720, rendered.Width);
+        Assert.Equal(600, rendered.Height);
+
+        // A labeled cell ("b-00" -> "LSDI") must have changed from the base.
+        OverlayRegion b00 = template.FindRegion("b-00")!;
+        Assert.True(RegionDiffers(baseImg, rendered, b00), "labelled region b-00 should differ from the base image");
+    }
+}