feat: add default_peer_rpc_url configuration to ProposerConfig

- Add default_peer_rpc_url field to ProposerConfig in config.py
- Pass default_peer_rpc_url to proposer_config in app.py and main.py
- Add Features Combined section to scenarios 19-20 for consistency
- Fix formatting in OPERATIONS_AUDIT.md Stage 9 section
- Add version metadata to training_schema.json

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

@@ -139,6 +139,7 @@ async def lifespan(app: FastAPI):
                     interval_seconds=settings.block_time_seconds,
                     max_block_size_bytes=settings.max_block_size_bytes,
                     max_txs_per_block=settings.max_txs_per_block,
+                    default_peer_rpc_url=settings.default_peer_rpc_url,
                 )
                 proposer = PoAProposer(config=proposer_config, session_factory=session_scope)
 

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

@@ -16,6 +16,7 @@ class ProposerConfig(BaseModel):
     interval_seconds: int
     max_block_size_bytes: int
     max_txs_per_block: int
+    default_peer_rpc_url: Optional[str] = None
 
 # Default island ID for new installations
 DEFAULT_ISLAND_ID = str(uuid.uuid4())

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

@@ -124,6 +124,7 @@ class BlockchainNode:
             interval_seconds=settings.block_time_seconds,
             max_block_size_bytes=settings.max_block_size_bytes,
             max_txs_per_block=settings.max_txs_per_block,
+            default_peer_rpc_url=settings.default_peer_rpc_url,
         )
 
     async def _ensure_genesis_for_chains(self) -> None: