Add pre-render hook for expression-aware post card data

[georgeolaru]

Summary

Add a narrow pre-render card hook in Nova Blocks so themes can inject expression-aware card render data before final markup generation.

Scope

• expose a post card profile filter
• expose a post card render-data filter before final markup
• preserve the existing post-markup filter for backward compatibility
• cover the new hook with a wp-eval contract test

Related

Required by the Anima post expression profiles feature.