🩹 Fix block rendering compatibility with SCF

[adrianmomorales]

Summary

• SCF reads render_callback from its internal block-types store, while ACF Pro reads it from the WordPress block registry
• Since acf-composer stores a closure as render_callback, SCF calls it directly — bypassing the acf_block_render_template action that acf-composer listens on
• This sets render_callback to false and render_template to the block class name in the ACF store, so SCF falls through to the render_template path and fires the action

Why

Secure Custom Fields (SCF) is the community fork of ACF after WP Engine acquired it. Projects migrating from ACF Pro to SCF find that custom blocks registered via acf-composer don't render — the editor shows an infinite spinner or a memory exhaustion error.

Backwards compatibility

ACF Pro ignores the store values and always uses the render_callback passed to register_block_type() (which remains acf_render_block_callback). This change is fully backwards-compatible.

Test plan

• Verify blocks render correctly in the editor with ACF Pro
• Verify blocks render correctly in the editor with SCF
• Verify blocks render correctly on the frontend with both

🤖 Generated with Claude Code