feat(world-state): add blockHash verification to syncImmediate

[spalladino]

Motivation

syncImmediate syncs world state to a target block number but does not verify block identity. If a reorg occurred and the world state is at the same height but on a different fork, the method returns early without detecting the mismatch. Additionally, skipThrowIfTargetNotReached was dead code with no caller ever passing true.

Approach

Added an optional typed BlockHash parameter to syncImmediate. When at or past the target height, the implementation checks the hash via getL2BlockHash before returning early. On mismatch it falls through to trigger a resync. After syncing, if the hash still doesn't match, it throws a WorldStateSynchronizerError with reason block_hash_mismatch. Removed the unused skipThrowIfTargetNotReached parameter entirely.

Changes

• stdlib: Updated WorldStateSynchronizer interface signature — replaced skipThrowIfTargetNotReached?: boolean with blockHash?: BlockHash
• world-state: Implemented block hash verification in ServerWorldStateSynchronizer.syncImmediate with pre-sync and post-sync checks
• p2p: Both tx pool v1 and v2 FeePayerBalanceEvictionRule now pass BlockHash from context.block.hash() on BLOCK_MINED events
• prover-node: Passes last block's header hash when syncing world state before creating proving jobs
• txe: Updated mock synchronizer parameter name and type
• world-state (tests): Added tests for hash match (early return), hash mismatch (triggers resync), and hash mismatch after sync (throws)
• p2p (tests): Updated mock expectations to verify blockHash is passed in BLOCK_MINED handlers

[AztecBot]

✅ Successfully backported to backport-to-v4-next-staging #21453.