feat: add --format switch for runtime artifact family filtering

README.md

@@ -41,6 +41,7 @@ The library ships a default CLI front-end that is meant to be a convenient start
 - Output directory.
 - SVG renderer selection.
 - **`--only`** (short `-l`): restrict the build to the jobs whose names are given. It accepts one or more names and may be repeated. Jobs that the selected ones depend on are still built as needed, so it is a resource-saving way to rebuild or verify only a subset of an entire icon set.
+- **`--format`** (short `-f`): restrict the build to the given artifact formats (`freedesktop`, `ico`, `msix`, `icns`). It accepts one or more formats and may be repeated. Sinks and sources of non-selected formats skip themselves at run time, while intermediate jobs (like temporary artifact producers) are unaffected and always run. Defaults to all formats.
 
 Because Assemblicon is a library, this CLI is not fixed. You can write your own entry point and extend (or replace) the standard argument parser with project-specific options.