🩹 Doc Gen v1.0.1 — Consistent Root Help and Banner

Doc Gen v1.0.1 is a focused patch release that makes bare CLI invocation match
the documented help and banner experience.

- Running `doc-gen` without a subcommand now shows the Doc Gen banner followed
  by root help.
- Bare root help exits successfully instead of being treated as an error.
- `doc-gen --no-banner` shows root help without banner artwork.
- Local production and development images built through Make now report the
  reviewed Doc Gen version instead of setuptools-scm's legacy `0.1.0`
  fallback.
- Explicit `doc-gen --help`, version output, initialization, generation,
  printing, analysis, and dry-run behavior remain unchanged.

```bash
doc-gen --version
doc-gen
doc-gen --no-banner
doc-gen structure generate . --dry-run
make c-build-prod
docker run --rm doc-gen-prod:latest --version
```

- Version: `v1.0.1`
- Previous version: `v1.0.0`
- Release type: patch
- Package compatibility: Python 3.9+
- Standard development/container runtime: Python 3.14
- Stability: stable

_Release: v1.0.1_
_Author: Devalltect / Rizky Fernandes_