- Add status fields to Receipt model (status, claimed_at, claimed_by)
- Add RECEIPT_CLAIM handling to state_transition.py with validation and reward minting
- Add type field to Transaction model for reliable transaction type storage
- Update router to use TransactionRequest model to preserve type field
- Update poa.py to extract type from mempool transaction content and store only original payload
- Add RECEIPT_CLAIM to GasType enum with gas schedule
- Add MESSAGE transaction type to router.py valid_types
- Add MESSAGE handling to state_transition.py (value=0, fee-only)
- Add GasType.MESSAGE to gas schedules
- Re-enable state root computation in poa.py
- Change SQLite journal_mode to WAL for corruption prevention
- Add chattr +C to setup.sh for Btrfs CoW prevention
- Add _compute_state_root helper function to compute Merkle Patricia Trie state root from account state
- Replace direct balance/nonce updates with state_transition.apply_transaction in block proposal
- Compute and set state_root for both regular blocks and genesis block
- Add state root verification in sync.py after importing blocks
- Add application-layer database validation with DatabaseOperationValidator class
