On initialization, scap should find and import any cli.Application subclasses in the current scap repository (PWD or a parent directory).
The immediate need is for adding a scap swat command which leverage the scap arg parse infrastructure. In the future it will allow more standardization of our cli tooling without polluting the scap package with random project-specific code. Further long-term vision: to refactor mediawiki-specific bits from scap2 into a plugin for scap3.