App-wide configuration cascade for the tag family. Resolves in
priority order:
Per-instance Input binding.
provideTagConfigAt(...) in a parent component's viewProviders.
provideTagConfig(...) at the application root.
Library defaults (this token's factory).
providedIn: 'root' with a default factory means consumers never
need to provide the token explicitly - inject(CNGX_TAG_CONFIG)
always resolves. Consumers who want overrides call
provideTagConfig(...features) in bootstrapApplication providers
(root cascade) or provideTagConfigAt(...features) in a component's
viewProviders (sub-tree cascade).