No banner option

I know there's already an option for a smaller banner, but I would love a `--no-banner` option.
I'm writing a CLI that outputs JSON. With the banner, the output is longer valid JSON, so you can't pipe into a tool like `jq`.

E.g.

```
./mytool generateJson | jq

binary created with jbundle.avelino.run
jq: parse error: Invalid numeric literal at line 1, column 8

```

Start by locating the CLI option parsing and the code that writes the banner. Add a `--no-banner` path while preserving the existing default behavior, then verify that JSON output from the generated binary can be piped to `jq` without a parse error.

Written by the indexing model from the issue text.