feat: add is_extended_promotional column and filter to components

[khozakhulile27-netizen]

Closes #92

What this adds

Some JLCPCB parts are "extended promotional" — they act as basic parts for a limited time. This PR exposes that data as a filterable column.

Changes

• lib/db/derivedtables/component-base.ts — adds is_extended_promotional: boolean to the BaseComponent interface
• lib/db/optimizations/component-extended-promotional-index.ts — new optimization that:
  1. Adds the is_extended_promotional column to the components table via ALTER TABLE if it doesn't exist
  2. Creates an index on it for fast filtering
• routes/components/list.tsx — adds is_extended_promotional as an optional boolean query param that filters results

Usage

GET /components/list.json?is_extended_promotional=true

[khozakhulile27-netizen]

Please review

[khozakhulile27-netizen]

Please I fix everything am requesting a review

[khozakhulile27-netizen]

@seveibar please review

[khozakhulile27-netizen]

@seveibar - Please review this PR when you have a moment. 🙏

This PR (#337) implements the is_extended_promotional column feature for issue #92. The implementation:

• Adds the new column to the BaseComponent interface
• Creates proper database optimization with indexing
• Implements the filter in the components list endpoint
• Follows existing winterspec + zod patterns

Ready for merge! 🙂