Update init-firewall.sh: Add api.openai.com to firewall configuration

Update README.md: Revise section titles for clarity, add a full tutorial link, and enhance Flutter installation instructions

Update init-firewall.sh: Add mcp.context7.com to firewall configuration

Update README.md: Add instructions for configuring git user in devcontainer

Update Dockerfile: Set ownership for Flutter installation and configure git safe.directory for node user

Enhance Dockerfile: Install Cloc for code line counting utility

Update README.md: Add usage instructions for dev container setup and update firewall rules for Flutter domains

Update README.md: Refine description of the dev container setup for Claude Code and Flutter development

Update README.md: Clarify Flutter command usage and enhance alias instructions

Update README.md: Add Flutter command usage instructions and locale configuration details

Update init-firewall.sh: Add additional domains for firewall configuration

Enhance Dockerfile: Add locales support and adjust Flutter installation permissions

Rename README -> README.md

Initial commit