Harden wordpress.bench dependency loading

[chubes4]

Summary

• Load wordpress.bench dependency/component plugins by plugin header discovery instead of assuming slug/slug.php.
• Replay callbacks registered by late-loaded plugins/bootstrap files for plugins_loaded and init before workloads run.
• Fail fast when a heavyweight plugin source declares a Composer package autoloader but the mounted dependency lacks vendor autoload files, preventing partial bootstrap workloads.

Verification

• npm run build
• npm run bench-bootstrap-files-smoke
• npm run recipe-bench-smoke
• Homeboy WooCommerce/Stripe rig now fails before workload execution with a clear missing vendor autoload diagnostic for the unbuilt WooCommerce dependency mount.

Notes

• Follow-up remains in the Homeboy/dependency-prep layer: the WooCommerce dependency mount must be built or replaced with a built artifact before the Stripe rig can run the heavyweight workload.
• Addresses dependency-loading hardening for wordpress.bench should load declared plugin dependencies in the benchmark request #570.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Implemented the bench loading hardening, fixture coverage, and local/Homeboy verification; Chris directed the scope and reviewed the runtime behavior.