engine(macos-arm64): 4.6.4 build (64fb5cc) — agent_skinned + branding fixes

Brings in the 4.6.4 build of the Tinqs engine fork:
- New agent_skinned module: MultiSkinnedMeshInstance3D (data plane,
  pure-CPU, PackedFloat32Array, lazy ImageTexture) +
  MultiSkinnedInstance3D (renderer, ShaderMaterial with 4-bone
  linear-blend skinning shader, samples the data source's bone texture
  via gl_InstanceID). 21 doctest cases all pass.
- Branding fixes: window titles (X11/Wayland), AppUserModelID
  (Windows), NSApp (macOS), TTS class, SDL window class, log tags
  (Android), proxy_tag + xdg_toplevel_icon (Wayland), HTML editor
  meta. Windows .ico/.manifest/.natvis/.rc all renamed godot_* ->
  tinqs_*.
- Version 4.6.3 -> 4.6.4.

Built on Kraken (macOS Apple Silicon). 134MB editor mono binary.
Verify on consumer side: shasum -a 256 of the copied binary must
match this manifest's sha256.

manifest.json

@@ -2,16 +2,16 @@
   "engine": {
     "macos-arm64": {
       "binary": "engine/macos-arm64/tinqs.macos.editor.arm64.mono",
-      "version": "4.6.3.stable.mono.custom_build.de00a306c",
+      "version": "4.6.4.stable.mono.custom_build.ad16dc90f",
       "engine_repo": "tinqs/engine",
-      "engine_commit": "de00a30",
-      "sha256": "1dd8fbad55d07d20daf040dd790669893ece9783569e5060273ece33e4b68441",
+      "engine_commit": "64fb5cc",
+      "sha256": "aa9652f9cb58ec2027b923a4e8f3fd9f15ca6e3231a7073e665f3c4f309770f1",
       "target": "editor",
-      "built_on": "2026-06-09",
-      "built_by": "Kraken (local build — pipeline not yet trusted/verified)",
+      "built_on": "2026-06-13",
+      "built_by": "Kraken (local build \u2014 engine 4.6.4 with agent_skinned module + branding fixes)",
       "toolchain": "Xcode 26.3 (Apple clang 17)",
       "scons_flags": "platform=macos target=editor arch=arm64 module_mono_enabled=yes vulkan",
-      "note": "Editor binary only, built from the squashed-history engine (de00a30). .NET assemblies (GodotSharp) are provided by the game project. Terrain3D macOS frameworks ship HERE (see terrain_3d below) — they are gitignored in the game repo. Run with the existing ariki-game project."
+      "note": "Editor binary, built from engine 64fb5cc (4.6.4). Includes the new agent_skinned module (MultiSkinnedMeshInstance3D data plane + MultiSkinnedInstance3D renderer, 21 doctest cases all pass) + branding fixes (Tinqs in window titles, AppUserModelID, MessageBox, NSApp, SDL class, TTS, log tags, HTML editor; Windows .ico/.manifest/.natvis/.rc all renamed godot_* -> tinqs_*). .NET assemblies (GodotSharp) are provided by the game project. Terrain3D macOS frameworks ship HERE (see terrain_3d below) \u2014 they are gitignored in the game repo. Run with the existing ariki-game project."
     },
     "windows-x64": {
       "binary": "engine/windows-x64/tinqs.windows.editor.x86_64.mono.exe",
@@ -22,7 +22,7 @@
       "sha256": "b86113409ab95ad68823f19192cdaea152824008f6560adbc55ab469304f660d",
       "target": "editor",
       "built_on": "2026-06-09",
-      "built_by": "Forge (Ozan's Windows box — local build)",
+      "built_by": "Forge (Ozan's Windows box \u2014 local build)",
       "toolchain": "MSVC VS BuildTools 2022 (vcvars amd64), SCons, mono glue + GodotSharp assemblies",
       "scons_flags": "platform=windows target=editor module_mono_enabled=yes",
       "note": "Branded editor binary (Tinqs app icon/splash/logos baked in). Built from engine 67d0322. .NET assemblies (GodotSharp) + the Terrain3D addon are provided by the game project. Run with the existing ariki-game project. console_binary = the .console.exe variant for terminal stdout."
@@ -36,12 +36,12 @@
       "sha256_release": "ca16b2a6afa80c382ffd578ebb6b31ce456a251ef8642e7d1addba79ef51d564",
       "engine_repo": "tinqs/engine",
       "engine_commit": "bb8fe2f",
-      "built_against_engine_binary": "de00a306c (ABI via dumped extension_api.json — engine binary itself UNCHANGED, keep using de00a30)",
+      "built_against_engine_binary": "de00a306c (ABI via dumped extension_api.json \u2014 engine binary itself UNCHANGED, keep using de00a30)",
       "built_on": "2026-06-09",
-      "built_by": "Kraken (engine/terrain3d/build.sh — dump API, scons editor+release, ad-hoc sign)",
-      "fix": "get_height no longer returns NaN at region borders (bilerp corners crossing a missing neighbor region propagated NaN for valid positions — the NaN-on-saved-.res bug the game shimmed around). Hole semantics unchanged.",
-      "install": "cp -R engine/macos-arm64/terrain_3d/bin/libterrain.macos.*.framework <ariki-game>/addons/terrain_3d/bin/ — the game's .gitignore (bin/) means these never come from game git on macOS.",
-      "note": "GDExtension only — no engine rebuild needed or performed. Verified: ariki-game itest 70/70 with these frameworks loaded."
+      "built_by": "Kraken (engine/terrain3d/build.sh \u2014 dump API, scons editor+release, ad-hoc sign)",
+      "fix": "get_height no longer returns NaN at region borders (bilerp corners crossing a missing neighbor region propagated NaN for valid positions \u2014 the NaN-on-saved-.res bug the game shimmed around). Hole semantics unchanged.",
+      "install": "cp -R engine/macos-arm64/terrain_3d/bin/libterrain.macos.*.framework <ariki-game>/addons/terrain_3d/bin/ \u2014 the game's .gitignore (bin/) means these never come from game git on macOS.",
+      "note": "GDExtension only \u2014 no engine rebuild needed or performed. Verified: ariki-game itest 70/70 with these frameworks loaded."
     }
   }
 }