Initial FrameAssistant baseline from the vrdashboard template

Template stripped to the overlay platform (examples, demo UI and Frame
test package removed), renamed to FrameAssistant, and working rules for
the project recorded in CLAUDE.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docker/cross-arm64.Dockerfile

@@ -0,0 +1,20 @@
+# Cross-compilation environment: x86_64 host tools + aarch64 target libraries via Debian
+# multiarch. The compiler runs natively (no QEMU); Qt's host tools (moc, rcc, qmlcachegen …)
+# are the amd64 builds, target Qt libraries are the arm64 builds.
+FROM debian:trixie
+
+ENV LANG=C.UTF-8
+
+RUN dpkg --add-architecture arm64 \
+ && apt-get update \
+ && apt-get install -y --no-install-recommends \
+        ca-certificates cmake ninja-build pkgconf file patchelf \
+        g++-aarch64-linux-gnu binutils-aarch64-linux-gnu \
+        qt6-base-dev qt6-base-dev-tools qt6-declarative-dev qt6-declarative-dev-tools \
+        qt6-base-dev:arm64 qt6-declarative-dev:arm64 \
+        libgl-dev:arm64 libegl-dev:arm64 libvulkan-dev:arm64 libxkbcommon-dev:arm64 \
+        qml6-module-qtquick:arm64 qml6-module-qtquick-controls:arm64 \
+        qml6-module-qtquick-layouts:arm64 qml6-module-qtquick-templates:arm64 \
+        qml6-module-qtqml-workerscript:arm64 qml6-module-qtquick-window:arm64 \
+        qt6-qpa-plugins:arm64 qt6-wayland:arm64 \
+ && rm -rf /var/lib/apt/lists/*