feat: multi-chain Soroban state synchronizer using CRDTs (#49)

[real-venus]

Multi-Chain Soroban Contract State Synchronizer Using CRDTs (#49)

Closes #49

What's included

File	Responsibility
src/types/crdt.ts	LamportTimestamp, LWWRegister, ORSet, VectorClock, the CrdtEvent discriminated union, resource diffs, and bounds (chain priority mainnet > testnet > futurenet, 12-ledger / ~60 s reconcile timeout).
src/utils/lamportClock.ts	LamportClock (tick / observe / tickAfter) and compareTimestamp — a total order by counter with chain-priority tie-breaking.
src/utils/crdtMerge.ts	Pure engine: LWW register merge, tag-based OR-set with tombstones (remove carries the observed tags, so merges are order-independent), orSetValues, and a batched mergeEvents producing per-resource diffs + vector clocks + chain-seen counters.
src/workers/crdtMerge.worker.ts	Accumulates the merged state off the main thread and posts diffs back.
src/store/slices/crdtSlice.ts	Applies diffs immutably, tracks per-resource vector clocks + per-chain lastSeen, and a staleness watcher that flags a chain for a full snapshot re-fetch past the reconcile timeout.
src/hooks/useContractState.ts	Stamps each ingested event with the originating chain's Lamport clock, batches to the worker (inline-merge fallback), runs the staleness watch, and auto-cleans on unmount.
tests/unit/*	Clock ordering, CRDT convergence under arbitrary interleavings (LWW tie-breaks, OR-set add-wins, commutativity), incremental folding, and the store/staleness watcher.