feat: add multi-chain support to blockchain explorer and update infrastructure configuration

- Add multi-chain support with ait-devnet, ait-testnet, ait-mainnet
- Add chain selector dropdown in explorer UI
- Add /api/chains endpoint to list supported chains
- Update all API endpoints to accept optional chain_id parameter
- Update RPC URL configuration to support multiple chains per network
- Change default port from 3001 to 8016 (enhanced services range)
- Update coordinator database path to ./

apps/coordinator-api/src/app/database.py

@@ -5,7 +5,7 @@ from sqlalchemy import StaticPool
 
 # Create in-memory SQLite database for now
 engine = create_engine(
-    "sqlite:////home/oib/windsurf/aitbc/apps/coordinator-api/aitbc_coordinator.db",
+    "sqlite:///./data/coordinator.db",
     connect_args={"check_same_thread": False},
     poolclass=StaticPool,
     echo=True  # Enable SQL logging for debugging
@@ -15,3 +15,7 @@ engine = create_engine(
 def create_db_and_tables():
     """Create database and tables"""
     SQLModel.metadata.create_all(engine)
+
+async def init_db():
+    """Initialize database by creating tables"""
+    create_db_and_tables()