flake: emit Unity bundle zip; add Gitea Actions CI/release; publish VPM index

- flake.nix: install the libaac cdylib alongside aac-dump and zip it with
  the C# Unity packages as the default package
- .gitea/workflows: build+package on push/PR, publish release on v* tags
- vpm: commit the repository index and packaging script, with VPM_INDEX and
  VPM_INDEX_URL overrides for generating a local listing

flake.nix

@@ -43,26 +43,58 @@
           };
           craneLib = (crane.mkLib pkgs).overrideToolchain rustToolchain;
 
+          # Name Unity expects on the current platform; AacCrabNative.cs imports "libaac".
+          nativeLib =
+            if pkgs.stdenv.hostPlatform.isDarwin then
+              "libaac.dylib"
+            else if pkgs.stdenv.hostPlatform.isWindows then
+              "aac.dll"
+            else
+              "libaac.so";
+
           # The Rust core: evaluates the Rhai DSL and emits the graph as JSON for Unity.
           aac = craneLib.buildPackage {
             src = ./rust;
             strictDeps = true;
             doCheck = true;
+            # crane's default install only copies binaries; install the cdylib explicitly.
+            installPhase = ''
+              runHook preInstall
+              mkdir -p $out/lib $out/bin
+              cp target/release/${nativeLib} $out/lib/
+              cp target/release/aac-dump $out/bin/
+              runHook postInstall
+            '';
           };
+
+          # Unity-importable bundle: native library plus the C# packages, as a single zip.
+          bundle =
+            pkgs.runCommand "animator-as-crab-${system}.zip"
+              {
+                nativeBuildInputs = [ pkgs.zip ];
+                meta.description = "Unity plugin bundle for animator-as-crab";
+              }
+              ''
+                mkdir -p root/Plugins root/bin
+                cp ${aac}/lib/${nativeLib} root/Plugins/
+                cp ${aac}/bin/aac-dump root/bin/
+                cp -r ${./csharp}/dev.doloro.animator-as-crab root/
+                cp -r ${./csharp}/dev.hai-vr.animator-as-code.v1.base.test root/
+                (cd root && zip -q -r $out .)
+              '';
         in
         {
           packages = {
-            inherit aac;
-            default = aac;
+            inherit aac bundle;
+            default = bundle;
           };
 
           devShells.default = craneLib.devShell {
             inputsFrom = [ aac ];
             packages = [
               rustToolchain
-              pkgs.dotnet-sdk
-              pkgs.mono
               pkgs.jq
+              pkgs.zip
             ];
           };