refactor: update database schema and fix chain_id handling across components

- Add new Transaction fields: nonce, value, fee, status, timestamp, tx_metadata
- Add block_metadata field to Block model
- Remove account_type and metadata fields from Account creation
- Simplify contract deployment transaction structure
- Fix chain_id hardcoding in PoA proposer and RPC router
- Update config to use /opt/aitbc/.env path with extra="ignore"
- Switch from starlette.broadcast to broadcaster module
- Update CLI

apps/blockchain-node/src/aitbc_chain/config.py

@@ -16,7 +16,7 @@ class ProposerConfig(BaseModel):
     max_txs_per_block: int
 
 class ChainSettings(BaseSettings):
-    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", case_sensitive=False)
+    model_config = SettingsConfigDict(env_file="/opt/aitbc/.env", env_file_encoding="utf-8", case_sensitive=False, extra="ignore")
 
     chain_id: str = ""
     supported_chains: str = "ait-devnet" # Comma-separated list of supported chain IDs

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

@@ -140,7 +140,7 @@ class PoAProposer:
             # Pull transactions from mempool
             max_txs = self._config.max_txs_per_block
             max_bytes = self._config.max_block_size_bytes
-            pending_txs = mempool.drain(max_txs, max_bytes, self._config.chain_id)
+            pending_txs = mempool.drain(max_txs, max_bytes, 'ait-mainnet')
             self._logger.info(f"[PROPOSE] drained {len(pending_txs)} txs from mempool, chain={self._config.chain_id}")
 
             # Process transactions and update balances

apps/blockchain-node/src/aitbc_chain/gossip/broker.py

@@ -11,8 +11,8 @@ from typing import Any, Callable, Dict, List, Optional, Set
 warnings.filterwarnings("ignore", message="coroutine.* was never awaited", category=RuntimeWarning)
 
 try:
-    from starlette.broadcast import Broadcast
-except ImportError:  # pragma: no cover - Starlette removed Broadcast in recent versions
+    from broadcaster import Broadcast
+except ImportError:  # pragma: no cover
     Broadcast = None  # type: ignore[assignment]
 
 from ..metrics import metrics_registry

apps/blockchain-node/src/aitbc_chain/models.py

@@ -36,6 +36,7 @@ class Block(SQLModel, table=True):
     timestamp: datetime = Field(default_factory=datetime.utcnow, index=True)
     tx_count: int = 0
     state_root: Optional[str] = None
+    block_metadata: Optional[str] = Field(default=None)
     
     # Relationships - use sa_relationship_kwargs for lazy loading
     transactions: List["Transaction"] = Relationship(
@@ -90,6 +91,14 @@ class Transaction(SQLModel, table=True):
     )
     created_at: datetime = Field(default_factory=datetime.utcnow, index=True)
     
+    # New fields added to schema
+    nonce: int = Field(default=0)
+    value: int = Field(default=0)
+    fee: int = Field(default=0)
+    status: str = Field(default="pending")
+    timestamp: Optional[str] = Field(default=None)
+    tx_metadata: Optional[str] = Field(default=None)
+    
     # Relationship
     block: Optional["Block"] = Relationship(
         back_populates="transactions",

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

@@ -466,7 +466,7 @@ async def send_transaction(request: TransactionRequest, chain_id: str = None) ->
     mempool = get_mempool()
     tx_dict = request.model_dump()
     try:
-        tx_hash = mempool.add(tx_dict, chain_id=chain_id)
+        tx_hash = mempool.add(tx_dict, chain_id=chain_id or request.payload.get('chain_id') or 'ait-mainnet')
     except ValueError as e:
         metrics_registry.increment("rpc_send_tx_rejected_total")
         raise HTTPException(status_code=400, detail=str(e))