Build offline OpenPrestige release bundles

Rename the injector and package it with an embedded payload for Windows, Linux, and macOS x64/ARM64. Add a core-only ImGui native build, multi-platform CI and release packaging, and shared per-user storage with legacy config migration.

build.gradle

@@ -87,12 +87,29 @@ java {
 }
 
 jar {
+    // Optional custom native builds take precedence over the upstream binaries.
+    from('build/core-natives') {
+        into 'prestige-natives'
+    }
+    from('build/arm-natives') {
+        into 'prestige-natives'
+    }
     // Unpack the shaded libs (imgui classes + native dll, ClassTransform) into the mod jar.
     from({
         configurations.shade.collect { it.isDirectory() ? it : zipTree(it) }
     }) {
         exclude 'META-INF/MANIFEST.MF', 'META-INF/*.SF', 'META-INF/*.RSA', 'META-INF/*.DSA'
         exclude 'module-info.class', 'META-INF/versions/**'
+        exclude 'imgui/extension/**'
+        if (file('build/core-natives/windows-x86_64/imgui-java64.dll').isFile()) {
+            exclude 'io/imgui/java/native-bin/imgui-java64.dll'
+        }
+        if (file('build/core-natives/linux-x86_64/libimgui-java64.so').isFile()) {
+            exclude 'io/imgui/java/native-bin/libimgui-java64.so'
+        }
+        if (file('build/core-natives/macos-universal/libimgui-java64.dylib').isFile()) {
+            exclude 'io/imgui/java/native-bin/libimgui-java64.dylib'
+        }
     }
     from({ zipTree(configurations.engineMappings.singleFile) }) {
         include 'mappings/mappings.tiny'