fix: heal chatbot_is_active on valid subscription (403 on session/init); add Contact Us form and SuperAdmin inbox

fix: billing page, book re-index, Readers UI, and info tooltips

Add SuperAdmin retailer API keys with priority over env and free scraping.

Fetch list prices during platform presence scans where retailers allow it.

Harden platform scan when Goodreads or ISBN metadata is partial.

Implement Enterprise Worth Roadmap (R-139–R-173).

Replace HTML platform scraping with API-first catalog hub.

Fix book URL import to extract full ISBN metadata and survive repeat fetches.

Fix regressions from admin modularization refactor.

Refactor admin API into service and repository layers.