engine(windows-x64): publish 4.7 editor + GodotSharp C# assemblies

- Update windows-x64 to engine 4f2e02e5b7 (Godot 4.7, branded). New editor +
  console binaries (was 4.6.5 / 420e74bf8, now discarded).
- Add GodotSharp/ (Api + Tools, 199MB) — REQUIRED for other agents/machines to
  build & run the C# game against this binary (dotnet build links these). Mirrors
  the consume model: build once, everyone consumes.
- manifest.json: version/commit/sha256 bumped, godotsharp path + install note added.

macos-arm64 still 4.6.5 — Kraken to rebuild for 4.7.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

@@ -1,2 +1,2 @@
-# Locally-extracted engine runtime (GodotSharp C# assemblies) — not tracked
-engine/windows-x64/GodotSharp/
+# GodotSharp C# assemblies are now TRACKED (LFS) so consumers can build/run the
+# C# game without building the engine themselves. See manifest.json godotsharp_install.