[raymondjacobson]

Retires user challenges and programmable reward redemption while keeping weekly Trending Tracks (tt) and Underground Trending (tut) generation and claims enabled.

• Claim-all and undisbursed queries return only active, unpaid trending awards; explicit non-trending claims return HTTP 410. User challenge listing returns an empty compatible response.
• Schedule only the two trending processors. Deactivate other challenge definitions without deleting award/payment history, and stop their notification trigger during mixed-version rollouts.
• Return HTTP 410 for code creation and coin redemption before any consumption, signing or transaction. Exclude coin_airdrop prizes from active selection/listing so retired redemption codes cannot still be offered as prizes; other prizes/history remain available.

Validation: targeted API integration tests passed against an isolated PostgreSQL database (claims, raw paid-marker exclusion, active definitions, retired routes, notification trigger, prizes). Weekly trending processor and scheduler tests passed. git diff --check passed.

Release notes: intentionally ends outstanding non-trending claims and code redemption; existing history is retained. Ship the app/notification removal before or alongside this API change to avoid stale prompts. Compatible with the existing trending plugin; no SDK signature, Solana program, or funding change. This does not invalidate signatures already issued on-chain.

Companion PRs: validator, oracle, weekly payout plugin, app, notifications. Each targets main independently; none requires a Solana program upgrade.