Document separate carrier and scoped parameter types

[robertvansteen]

Summary

• add end-to-end coverage for sparse rows entering through a declared list input
• demonstrate that a permissive carrier element type can coexist with a stricter scoped parameter type
• document that the source compiler owns the narrower declaration passed to scope()

Context

Axiom #100 added projected admission for compiled scopes. The original quantifier test supplied its collection through a definition, so it exercised scoped admission without exercising the outer program boundary. A real host may admit a collection through a permissive input type while compiling each scoped predicate against a stricter authored parameter type.

This PR covers that public-seam composition and documents the contract. The collection crosses its own boundary honestly, then each scoped invocation admits only the parameter fields its body reads. No production behavior changes are required.

Verification

• composer test:types
• composer test:unit — 1,311 tests, 4,987 assertions, 100% line coverage