Add is_extended_promotional filter to components list and API search

[gavin-openops]

/claim #92

Summary

• Added is_extended_promotional as an optional query param on:
  • /components/list(.json)
  • /api/search
• Added SQL filtering via json_extract(extra, "$.is_extended_promotional") = 1
• Added is_extended_promotional to response payloads by parsing each component's extra JSON
• Also fixed an existing omission in routes/components/list.tsx by selecting preferred so is_preferred in output works correctly

Why

Issue #92 asks for extended promotional status to be available in a filterable column. This change exposes and filters that status without requiring a schema migration, since the flag is already available from component extra JSON.

Validation

• bun run format ✅
• bun run format:check ✅
• bun test ⚠️ existing unrelated fixture/db issues in this repo (missing tables for some integration tests), but no new formatting/type errors introduced by this change.

If maintainers prefer this flag materialized as a dedicated DB column in derived tables, I can follow up with that migration path too.