remove unused queue.py module and refactor chain_id handling in CLI

Deleted aitbc/queue.py containing TaskQueue, JobScheduler, BackgroundTaskManager, and WorkerPool classes that were not being used in the codebase.

Refactored chain_id handling in CLI to use centralized get_chain_id utility function instead of duplicating chain_id detection logic in send_transaction, get_balance, and agent_operations functions.

cli/aitbc_cli/config.py

@@ -30,6 +30,9 @@ class CLIConfig(BaseAITBCConfig):
     wallet_url: str = Field(default="http://localhost:8003", description="Wallet daemon URL (alias for compatibility)")
     blockchain_rpc_url: str = Field(default=f"http://localhost:{BLOCKCHAIN_RPC_PORT}", description="Blockchain RPC URL")
     
+    # Chain configuration
+    chain_id: str = Field(default="ait-mainnet", description="Default chain ID for multichain operations")
+    
     # Authentication
     api_key: Optional[str] = Field(default=None, description="API key for authentication")