Quantum Compute

Reviewed overlay for SN48 using the official qBittensor Labs website and Quantum Compute source repository. This pass fixed 3 surfaces having no probe config at all -- the registry-wide gap tracked in #5932. Re-checked for an OpenAPI schema (qbittensorlabs.com and openquantum.com both without one) -- gap_notes remain accurate. All 4 surfaces re-verified live. Dropped the qbittensorlabs.com/api/health surface (#6328): it's a generic site-liveness ping (byte-identical {"status":"ok"} response, same ETag, served on both www.qbittensorlabs.com and www.openquantum.com) carrying no subnet-specific data, and the quantum-compute repository never references qbittensorlabs.com as SN48's own domain -- kept exclusively on enigma.json (SN63), whose repository does.