Expose extended promotional component filter

[absalonCRC]

Summary

• derive and expose is_extended_promotional from existing component flags (preferred && !basic) in /api/search and /components/list responses
• add is_extended_promotional=true filtering to the legacy routes and Cloudflare/D1 search paths
• add an Extended Promotional checkbox to the components list UI and render coverage for the Cloudflare table path
• fixes /components/list selecting preferred before mapping is_preferred
• updates the setup 7-Zip download URLs from removed 7z2408 archives to current official 7z2600 archives
• switches PR tests to a small seeded SQLite fixture so CI does not rebuild/download the full production catalog
• resets the DB singleton after destroy() so setup code cannot leave later route tests with a dead Kysely client

Verification

• bun test
• bunx tsc --noEmit
• bunx biome format .
• cd cf-proxy && bunx tsc --noEmit
• cd cf-proxy && bunx biome format .
• bun run scripts/setup-7z.ts
• cd cf-proxy && bun test test/render.test.ts

/claim #92

Payment fallback if needed: PayPal cultofrozen@gmail.com

[absalonCRC]

Status update for review:

• Scope matches Add is_extended_promotional column to components (from data source) #92: exposes and filters is_extended_promotional across /components/list, /api/search, and the Cloudflare/D1 search paths.
• Derivation is intentionally narrow: preferred && !basic, using the existing JLC source flags.
• PR includes route/UI coverage plus helper coverage.
• Current checks are green: Bun Test, Format Check, and Type Check.

The PR body already includes /claim #92 for the bounty flow.