getPinnedChainCheckpoint

The CHECKPOINT block the persisted caches were built against — a per-chain-instance identity for detecting a chain RESET. It is a block ABOVE genesis (height + hash): a localnet booting from a fixed chain spec reproduces the same GENESIS hash across a reset, so genesis can't be the discriminator, but any higher block carries a per-instance timestamp and so a per-instance hash. com.midnight.kuira.core.indexer.sync.ChainResetGuard re-looks-up this height on each sync; a missing block (shorter fresh chain) or a changed hash means a reset.

Lives in the same "sync_state" DataStore as the tx cursor but is NOT touched by clearSyncState (which clears only the cursor), so the guard can re-pin it to the new chain AFTER wiping the stale caches (crash-safe re-pin-last). clearAllSyncState does clear it.