Change Product/ProductTranslation from "override/inheritance" pattern (NULL = inherit from marketplace) to "independent copy" pattern (all fields populated at creation). Key changes: - Remove OVERRIDABLE_FIELDS, effective_* properties, reset_* methods - Rename get_override_info() → get_source_comparison_info() - Update copy_to_vendor_catalog() to copy ALL fields + translations - Replace effective_* with direct field access in services - Remove *_overridden fields from schema, keep *_source for comparison - Add migration to populate NULL fields from marketplace products The marketplace_product_id FK is kept for "view original source" feature. Rollback tag: v1.0.0-pre-product-independence 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Generic single-database configuration.