Osero Prime Renames Prysm Chainlog Keys for Consistency

Osero Prime governance proposes renaming two Chainlog keys for naming consistency with other Primes. Proposed changes: PRYSM_SUBPROXY to OSERO_SUBPROXY, and PRYSM_STARGUARD to OSERO_STARGUARD. Addresses remain unchanged. Aligns with Keel and Grove conventions; classified as a housekeeping item.