feat: implement MESSAGE transaction type and re-enable state root computation

- 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

apps/blockchain-node/src/aitbc_chain/consensus/poa.py

@@ -24,29 +24,29 @@ def _sanitize_metric_suffix(value: str) -> str:
     return sanitized or "unknown"
 
 
-# def _compute_state_root(session: Session, chain_id: str) -> str:
-#     """Compute state root from current account state."""
-#     try:
-#         state_manager = StateManager()
-#         
-#         # Get all accounts for this chain
-#         accounts = session.exec(
-#             select(Account).where(Account.chain_id == chain_id)
-#         ).all()
-#         
-#         # Convert to dictionary
-#         account_dict = {acc.address: acc for acc in accounts}
-#         
-#         # Compute state root
-#         root = state_manager.compute_state_root(account_dict)
-#         
-#         # Return as hex string
-#         return '0x' + root.hex()
-#     except Exception as e:
-#         # If state root computation fails, return None for now
-#         # This can happen during genesis block creation when accounts don't exist yet
-#         logger.warning(f"Failed to compute state root: {e}")
-#         return None
+def _compute_state_root(session: Session, chain_id: str) -> str:
+    """Compute state root from current account state."""
+    try:
+        state_manager = StateManager()
+        
+        # Get all accounts for this chain
+        accounts = session.exec(
+            select(Account).where(Account.chain_id == chain_id)
+        ).all()
+        
+        # Convert to dictionary
+        account_dict = {acc.address: acc for acc in accounts}
+        
+        # Compute state root
+        root = state_manager.compute_state_root(account_dict)
+        
+        # Return as hex string
+        return '0x' + root.hex()
+    except Exception as e:
+        # If state root computation fails, return None for now
+        # This can happen during genesis block creation when accounts don't exist yet
+        logger.warning(f"Failed to compute state root: {e}")
+        return None
 
 
 
@@ -287,6 +287,9 @@ class PoAProposer:
             # Compute block hash with transaction data
             block_hash = self._compute_block_hash(next_height, parent_hash, timestamp, processed_txs)
 
+            # Compute state root from account state
+            state_root = _compute_state_root(session, self._config.chain_id)
+
             block = Block(
                 chain_id=self._config.chain_id,
                 height=next_height,
@@ -295,7 +298,7 @@ class PoAProposer:
                 proposer=self._config.proposer_id,
                 timestamp=timestamp,
                 tx_count=len(processed_txs),
-                state_root=None,  # Temporarily disabled for debugging
+                state_root=state_root,
             )
             session.add(block)
             session.commit()
@@ -358,6 +361,9 @@ class PoAProposer:
                 self._logger.info(f"Genesis block with hash {block_hash} already exists, skipping creation")
                 return
             
+            # Compute state root for genesis block
+            state_root = _compute_state_root(session, self._config.chain_id)
+            
             genesis = Block(
                 chain_id=self._config.chain_id,
                 height=0,
@@ -366,7 +372,7 @@ class PoAProposer:
                 proposer="genesis",  # Use "genesis" as the proposer for genesis block to avoid hash conflicts
                 timestamp=timestamp,
                 tx_count=0,
-                state_root=None,  # Temporarily disabled for debugging
+                state_root=state_root,
             )
             session.add(genesis)
             try:

apps/blockchain-node/src/aitbc_chain/economics/gas.py

@@ -17,6 +17,10 @@ class GasType(Enum):
     VALIDATOR_STAKE = "validator_stake"
     AGENT_OPERATION = "agent_operation"
     CONSENSUS = "consensus"
+    MESSAGE = "message"
+    RECEIPT_CLAIM = "receipt_claim"
+    GPU_MARKETPLACE = "gpu_marketplace"
+    EXCHANGE = "exchange"
 
 @dataclass
 class GasSchedule:
@@ -91,6 +95,12 @@ class GasManager:
                 base_gas=80000,
                 gas_per_byte=0,
                 complexity_multiplier=1.0
+            ),
+            GasType.MESSAGE: GasSchedule(
+                gas_type=GasType.MESSAGE,
+                base_gas=21000,
+                gas_per_byte=0,
+                complexity_multiplier=1.0
             )
         }
     

apps/blockchain-node/src/aitbc_chain/rpc/router.py

@@ -173,7 +173,7 @@ def _serialize_receipt(receipt: Receipt) -> Dict[str, Any]:
 
 
 class TransactionRequest(BaseModel):
-    type: str = Field(description="Transaction type, e.g. TRANSFER, RECEIPT_CLAIM, GPU_MARKETPLACE, EXCHANGE")
+    type: str = Field(description="Transaction type, e.g. TRANSFER, RECEIPT_CLAIM, GPU_MARKETPLACE, EXCHANGE, MESSAGE")
     sender: str
     nonce: int
     fee: int = Field(ge=0)
@@ -183,7 +183,7 @@ class TransactionRequest(BaseModel):
     @model_validator(mode="after")
     def normalize_type(self) -> "TransactionRequest":  # type: ignore[override]
         normalized = self.type.upper()
-        valid_types = {"TRANSFER", "RECEIPT_CLAIM", "GPU_MARKETPLACE", "EXCHANGE"}
+        valid_types = {"TRANSFER", "RECEIPT_CLAIM", "GPU_MARKETPLACE", "EXCHANGE", "MESSAGE"}
         if normalized not in valid_types:
             raise ValueError(f"unsupported transaction type: {normalized}. Valid types: {valid_types}")
         self.type = normalized

apps/blockchain-node/src/aitbc_chain/state/state_transition.py

@@ -68,20 +68,33 @@ class StateTransition:
         if tx_nonce != expected_nonce:
             return False, f"Invalid nonce for {sender_addr}: expected {expected_nonce}, got {tx_nonce}"
         
+        # Get transaction type
+        tx_type = tx_data.get("type", "TRANSFER").upper()
+        
         # Validate balance
         value = tx_data.get("value", 0)
         fee = tx_data.get("fee", 0)
-        total_cost = value + fee
+        
+        # For MESSAGE transactions, value must be 0
+        if tx_type == "MESSAGE" and value != 0:
+            return False, f"MESSAGE transactions must have value=0, got {value}"
+        
+        # For MESSAGE transactions, only check fee
+        if tx_type == "MESSAGE":
+            total_cost = fee
+        else:
+            total_cost = value + fee
         
         if sender_account.balance < total_cost:
             return False, f"Insufficient balance for {sender_addr}: {sender_account.balance} < {total_cost}"
         
-        # Get recipient account
+        # Get recipient account (not required for MESSAGE)
         recipient_addr = tx_data.get("to")
-        recipient_account = session.get(Account, (chain_id, recipient_addr))
-        
-        if not recipient_account:
-            return False, f"Recipient account not found: {recipient_addr}"
+        if tx_type != "MESSAGE":
+            recipient_account = session.get(Account, (chain_id, recipient_addr))
+            
+            if not recipient_account:
+                return False, f"Recipient account not found: {recipient_addr}"
         
         return True, "Transaction validated successfully"
     
@@ -114,17 +127,27 @@ class StateTransition:
         recipient_addr = tx_data.get("to")
         
         sender_account = session.get(Account, (chain_id, sender_addr))
-        recipient_account = session.get(Account, (chain_id, recipient_addr))
+        
+        # Get transaction type
+        tx_type = tx_data.get("type", "TRANSFER").upper()
         
         # Apply balance changes
         value = tx_data.get("value", 0)
         fee = tx_data.get("fee", 0)
-        total_cost = value + fee
+        
+        # For MESSAGE transactions, only deduct fee
+        if tx_type == "MESSAGE":
+            total_cost = fee
+        else:
+            total_cost = value + fee
+            recipient_account = session.get(Account, (chain_id, recipient_addr))
         
         sender_account.balance -= total_cost
         sender_account.nonce += 1
         
-        recipient_account.balance += value
+        # For MESSAGE transactions, skip recipient balance change
+        if tx_type != "MESSAGE":
+            recipient_account.balance += value
         
         # Mark transaction as processed
         self._processed_tx_hashes.add(tx_hash)
@@ -132,7 +155,7 @@ class StateTransition:
         
         logger.info(
             f"Applied transaction {tx_hash}: "
-            f"{sender_addr} -> {recipient_addr}, value={value}, fee={fee}"
+            f"{sender_addr} -> {recipient_addr}, value={value}, fee={fee}, type={tx_type}"
         )
         
         return True, "Transaction applied successfully"