Remote-cluster Supabase creds in shared ltm.md - attribution leak, VENUS-350 sibling of OPS-191

ltm.md (sole global memory file, every venus agent reads it) holds agent_db_mars_cc / agent_db02_mars_cc per-agent Supabase login passwords for a REMOTE cluster - attribution defeated by construction since the whole fleet can read the one file, same failure class as OPS-191 but different cluster/file/scope (sibling: OPS-191 is local-venus-cluster stray creds only). Separately, one entry is annotated 'saved from db-pluto-cc' - a scraped postgres superuser password, not an attribution row at all. Measure-and-report only per VENUS-350 convention - do NOT touch/rotate the values, Elazar owns every remediation call.