fix(with-resource): preserve hasValue narrowing

[rainerhahnekamp]

Summary

• model hasValue as a function property with an explicit generic receiver
• preserve the concrete SignalStore type while narrowing value() to exclude undefined
• turn the existing inferred-consumer type tests into positive narrowing assertions

Verification

• full pre-commit verify:all (lint, test, and build for the library and demo)
• focused TypeScript compilation confirms the three hasValue narrowing assertions; one unrelated existing AddressResolver.address fixture error remains

[michael-small]

This change seems great for unnamed resources, but it does not fix named resources.

Repro branch commit, with examples you can intelisense in a component HTML/TS as well as a purposely broken test: ngrx-toolkit/ngrx-toolkit@5b8cb34

[rainerhahnekamp]

@michael-small, thanks for your commit on the unnamed resources. I have added some docu about the why and if you approve, we can merge and relase v22

[michael-small]

LGTM