feat: pin and Extract world state with adaptive paging

[kant777]

Pin debug state export to a fixed block with adaptive paging + storage handling

Summary

This PR updates the world-state → genesis exporter to reliably dump account balances, nonces, contract code, and (optionally) storage from an Erigon/Geth node—even under heavy state and strict RPC timeouts.

• Pinned snapshot: Resolve latest once to a specific block number, print it, and use that same hex block for all calls.
• Adaptive paging: Auto-reduce page sizes on timeouts for both accounts and storage.
• Targeted storage export: Page storage per-contract only when requested, avoiding giant monolithic dumps.
• Resilient merging: Preserve existing alloc entries and overlay the snapshot.

Why

Previous approaches could:

• Time out on debug_dumpBlock or fat debug_accountRange calls.
• Fail with missing trie node … loc: diff if the chain advanced mid-scan.
• Over-fetch storage/code unnecessarily, causing instability on pruned nodes.

This PR fixes those by pinning the block and keeping RPC calls small and consistent.

What changed

• Block pinning: latest → decimal block → single hex tag used for:
  • debug_accountRange(blockHex, start, n, true, true, true) (lightweight)
  • eth_getCode(addr, blockHex)
  • debug_storageRangeAt(blockHex, null, addr, startKey, n)
• Adaptive pagination:
  • Accounts: halve --page-size on timeout down to --min-page-size.
  • Storage: halve --storage-page-size on timeout down to --storage-min-page-size.
• Optional storage: Only fetched when --include-storage is set. Non-zero slots are included in alloc.storage.
• Graceful degradation: If storage paging hits missing trie node (pruned node), we warn and continue with balances/nonces/code.
• UX: Prints the exact block number being exported and a final output path.

Usage

python3 world_state4.py \
  --rpc http://<node>:8545 \
  --input-genesis initial_genesis.json \
  --output out_genesis.json \
  --include-code --include-storage \
  --page-size 2048 \
  --min-page-size 256 \
  --storage-page-size 2048 \
  --storage-min-page-size 128 \
  --rpc-timeout 300