Speed up replay hot paths

[smcio]

• compute and reuse immutable transaction message identities instead of repeatedly serializing and hashing messages
• batch and selectively cache AccountsDB reads, use bounded Pebble iterator ranges, and expose detailed loader/cache/index timings
• publish fold state through a short pending-view boundary so account readers do not wait through Pebble index commit/fsync
• remove the residual global modified-account publication lock when the overlay delta is already authoritative
• skip redundant LtHash input deduplication for the already-unique overlay delta
• avoid repeatedly decoding full account-record manifests during transaction-status checkpoint retention
• add detailed transaction publication, sysvar read, vote reward, LtHash, and BankHash diagnostics