Fix Docker build issues on Windows and non-ARM architectures

When attempting to install Claude Code on Windows 11 with an x86_64 architecture system, the dev container build fails with two critical errors:

1. Architecture mismatch: The Dockerfile attempts to install the ARM64 version of git-delta, resulting in the following error:

ERROR: failed to solve: process "/bin/sh -c wget https://github.com/dandavison/delta/releases/download/0.18.2/git-delta_0.18.2_arm64.deb && sudo dpkg -i git-delta_0.18.2_arm64.deb && rm git-delta_0.18.2_arm64.deb" did not complete successfully: exit code: 1

1. Script execution failure: After fixing the architecture issue, the container fails to execute the firewall initialization script:

Running the postCreateCommand from devcontainer.json...
sudo: unable to execute /usr/local/bin/init-firewall.sh: No such file or directory
postCreateCommand from devcontainer.json failed with exit code 1

I've submitted a PR (#61 ) that addresses these issues by making the container build process architecture-aware and fixing Windows line ending problems.