diff --git a/.docker/core.bake.Dockerfile b/.docker/core.bake.Dockerfile
index 60418c04c4..28581f1006 100644
--- a/.docker/core.bake.Dockerfile
+++ b/.docker/core.bake.Dockerfile
@@ -26,7 +26,6 @@ FROM ubuntu:24.04 AS vcpkg-base
         pkg-config \
         cmake \
         ninja-build \
-        mono-devel \
         && rm -rf /var/lib/apt/lists/*
 
     # Install vcpkg
@@ -39,31 +38,20 @@ FROM ubuntu:24.04 AS vcpkg-base
     ENV VCPKG_ROOT=/opt/vcpkg
     ENV PATH="${VCPKG_ROOT}:${PATH}"
 
-    ENV VCPKG_BINARY_SOURCES="clear;nuget,NuGetCache,readwrite;nugettimeout,3600"
+    ENV VCPKG_BINARY_SOURCES="clear;files,/nuget-cache,readwrite"
 
 
 FROM vcpkg-base AS vcpkg-local
 
-    RUN vcpkg fetch nuget && \
-        mkdir /nuget-cache && \
-        mono $(vcpkg fetch nuget) sources add \
-            -Source "/nuget-cache" \
-            -Name "NuGetCache"
+    RUN mkdir -p /nuget-cache
 
 
 FROM vcpkg-base AS vcpkg-remote
 
     ARG NUGET_REMOTE_URL
-    ARG NUGET_USERNAME
-    ARG NUGET_PASSWORD
-
-    RUN vcpkg fetch nuget && \
-        mono $(vcpkg fetch nuget) sources add \
-            -Source "${NUGET_REMOTE_URL}" \
-            -Name "NuGetCache" \
-            -Username "${NUGET_USERNAME}" \
-            -Password "${NUGET_PASSWORD}" \
-            -StorePasswordInClearText
+
+    RUN mkdir -p /nuget-cache
+    # Remote file cache: mount or pre-populate /nuget-cache from ${NUGET_REMOTE_URL} as needed
 
 
 
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 375f876dfb..c0eb93fc0c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -10,6 +10,7 @@ jobs:
       PLEASE_PRELOAD_LIBSTDCPP: true
       CC: clang-13
       CXX: clang++-13
+      VCPKG_BINARY_SOURCES: "clear;x-gha,readwrite"
 
     steps:
     - name: Checkout repository
@@ -73,12 +74,20 @@ jobs:
 
         echo "clang and clang-13 are both v13"
 
+    - name: Expose GitHub Actions cache tokens for vcpkg x-gha backend
+      uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+      with:
+        script: |
+          core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
+          core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
+
     - name: Set up vcpkg
       uses: lukka/run-vcpkg@v11
 
     - name: Configure core, build third_party libs (ICU, V8, etc.)
       run: |
-        cmake -GNinja -S . -B build -DVCPKG_TARGET_TRIPLET=x64-linux-dynamic -DCMAKE_TOOLCHAIN_FILE=${{ env.VCPKG_ROOT }}/scripts/buildsystems/vcpkg.cmake -DVCPKG_MANIFEST_MODE=ON -DVCPKG_MANIFEST_DIR=.
+        TRIPLET=${{ runner.arch == 'ARM64' && 'arm64-linux-dynamic' || 'x64-linux-dynamic' }}
+        cmake -GNinja -S . -B build -DVCPKG_TARGET_TRIPLET=${TRIPLET} -DCMAKE_TOOLCHAIN_FILE=${{ env.VCPKG_ROOT }}/scripts/buildsystems/vcpkg.cmake -DVCPKG_MANIFEST_MODE=ON -DVCPKG_MANIFEST_DIR=.
 
     - name: Build core (x2t, docbuilder, etc.)
       run: |