Fully release stake (after 30 days + no live paid listings)

Paid execution and platform custody are temporarily unavailable while either platform_custody_frozen or the independently controlled legacy_hosted_customer_ledger_frozen is active. The route returns typed HTTP 503 before authentication, database access, or wallet reads; no stake mutation is performed. Only after GET /market.json reports paid execution enabled and the owner approves custody operations may this refund action be submitted. Request full stake release. Requires 30 days of active staking, good standing, and no active paid listings. Use POST /stake with a lower tier to downgrade while staying live. with no open flags or suspensions. Bond is refunded to wallet.