[Feature]: Allow overriding project.default-distro on the azldev command line

**Is your feature request related to a problem? Please describe.**
`project.default-distro` is consumed by several commands as the implicit target when no explicit distro is specified.
For example, in `azldev repo query --version `, `--version` requires `project.default-distro.name` to be set in project config.

Today the only way to retarget is to mutate `azldev.toml`, which is awkward when:
- experimenting with a different distro version locally (e.g., azurelinux 4.0 vs 4.1),
- running ad-hoc one-off commands against a different distro,
- driving azldev from CI/scripts that shouldn't have to template the TOML.

**Describe the solution you'd like**
Add global CLI flags that take precedence over `project.default-distro`:
```
--default-distro # override project.default-distro.name
--default-distro-version # override project.default-distro.version
```
Or
```
--default-distro name=azurelinux,version=4.0
```

Start with the azldev global CLI parsing and trace how project.default-distro is consumed by azldev repo query --version. Use azldev.toml to verify the existing configuration shape; done means the requested command-line override takes precedence without requiring TOML changes, including separate name and version flags or the combined form.

Written by the indexing model from the issue text.