Add extended promotional component filter

[kimutaiRop]

Summary

• add an is_extended_promotional flag to derived component catalog/search-index data
• expose the flag in /components/list JSON and table rendering
• add a filter checkbox for extended promotional parts and wire it into search queries

/claim #92
Fixes #92

Tests

• bun test tests/build-derived-sync-db.test.ts cf-proxy/test/render.test.ts
• bun run format:check
• bash -n cf-proxy/scripts/sync-db.sh cf-proxy/scripts/rebuild-search-index-batched.sh
• bun test cf-proxy/test/contracts.test.ts