Support --profile-file flag in the gateway.

[cmrigney]

What I did

Added support for --profile-file flag in the gateway.

Example usage

# Export a profile ("default" in this example)
docker mcp profile export default default.yaml

# Use it to run the gateway
docker mcp gateway run --profile-file default.yaml

# Check default.yaml and your mcp.json with the gateway command into your git repo...

Related issue

(not mandatory) A picture of a cute animal, if possible in relation to what you did