Adds loadAppAuthzCatalog(appDir) to @wrnexus/dev-server: discovers
app/authz/*.ts declarations via buildRouter, imports and merges them
into an AuthzCatalog, returning an empty catalog when the app has no
declarations. A declaration with no default export is skipped with a
warning; a genuine conflict between two declarations throws
WRN-AUTHZ-CONFLICT naming both source files.
Declared the missing @wrnexus/authz workspace dependency in
dev-server's package.json.
