Function accept_rfq_quote_inner 

pub async fn accept_rfq_quote_inner(
    rfq_manager: &RfqManager,
    agent_auth: &dyn AgentAuthProvider,
    rfq_id_str: &str,
    quote_id_str: &str,
    wallet_address: WalletAddress,
    nonce: u64,
    signature: &str,
    chain_id: u64,
) -> Result<RfqAcceptResponse, String>

Core RFQ accept logic shared by the REST handler and the WebSocket handler.

Parses IDs, verifies the taker EIP-712 AcceptRFQQuote signature, checks agent authorization, and delegates to RfqManager::accept_quote.