feat(docker): add linux-arm64 QEMU runner Dockerfile and README

docker/qemu-runner/Dockerfile

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+FROM ubuntu:latest
+
+RUN apt-get update && apt-get install -y \
+  qemu-user-static \
+  binfmt-support \
+  libc6-arm64-cross \
+  && apt-get clean \
+  && rm -rf /var/lib/apt/lists/*
+
+# match expectations for lib locations
+RUN ln -s /usr/aarch64-linux-gnu/lib/ld-linux-aarch64.so.1 /lib/ \
+  && ln -s /usr/aarch64-linux-gnu/lib/ /lib/aarch64-linux-gnu
+
+WORKDIR /app
+
+# ENV QEMU_STRACE=1
+
+ENTRYPOINT ["qemu-aarch64-static"]

docker/qemu-runner/README.md

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+# QEMU Runner Docker Image
+
+This Docker image provides an environment for running binaries on `x64` built
+for `linux-arm64` using QEMU user-mode emulation. The image could be extended
+for other architectures.
+
+## Build the Image
+
+```bash
+docker build -t zkn/qemu-runner:latest .
+```
+
+## Example Usage
+
+### Start a Container with Bash
+
+Run the container interactively with a mounted directory:
+
+```bash
+docker run --rm -ti -v "$(pwd)/ws:/app" --entrypoint bash zkn/qemu-runner:latest
+```
+
+### Run Binary `walletshield-linux-arm64`
+
+Prepare a directory (`./ws/` for example) containing the necessary files:
+
+1. The `walletshield-linux-arm64` binary.
+2. A network deployment client configuration file (e.g., `client.toml`).
+
+Run the binary inside the container:
+
+```bash
+# display help
+docker run --rm -ti -v "$(pwd)/ws:/app" zkn/qemu-runner:latest /app/walletshield-linux-arm64 --help
+
+# listen for RPC requests using the network client configuration:
+docker run --rm -ti -v "$(pwd)/ws:/app" zkn/qemu-runner:latest /app/walletshield-linux-arm64 -config /app/client.toml -listen :7070
+```
+
+Notes:
+
+- Ensure the binary has execute permissions.
+- Ensure the binaries and configuration files are placed in the `ws` directory for mounting into the container.
+
+## Using `QEMU_STRACE` for Debugging
+
+The `QEMU_STRACE` environment variable enables detailed tracing of system calls
+made by the emulated binary. This is useful for debugging issues with the
+emulation such as missing dynamic libraries or incorrect paths.
+
+### Enable QEMU_STRACE
+
+To enable tracing, set the `QEMU_STRACE` environment variable using the `-e` option when running the container:
+
+```bash
+docker run --rm -ti -v "$(pwd)/ws:/app" -e QEMU_STRACE=1 zkn/qemu-runner:latest /app/walletshield-linux-arm64 --help
+```