Seed a paid wallet UX child bounty

Create and fully fund a concrete wallet UX coding bounty that a different registered participant completes and receives canonical settlement for.

Work state: claimable. Payment state: escrowed. Committed reward: 900000 USDC (base_units; 6 decimals). Verification: deterministic_module. Next action: Run the wallet-neutral readiness check before requesting a claim. Do not provide a private key or seed phrase.