[bug]: DX Issues with ShelbyNetwork type & ShelbyRPCClient.putBlob error messaging

[adityaypz]

Affected product

SDK (JS/TS)

Version / Commit / Build

@shelby-protocol/sdk/node latest

Platform / Environment

Node

Steps to Reproduce

1. Setup a Node.js project using TypeScript and @shelby-protocol/sdk.
2. Enable strict: true in tsconfig.json.
3. Try to configure a client using ShelbyNetwork as a value:
   const client = new ShelbyClient({ network: ShelbyNetwork.Devnet });
4. Try to upload a blob directly using ShelbyRPCClient.putBlob without first registering the commitments on-chain via the coordination client.

Expected Behavior

1. ShelbyNetwork should be usable as a configuration value without throwing a TypeScript error.
2. ShelbyRPCClient.putBlob should return a clear developer-friendly error (e.g., 400 Bad Request or a descriptive message) if on-chain commitments haven't been made, explaining what step the developer missed.

Actual Behavior & Errors

1. TypeScript strict mode throws an error when trying to use ShelbyNetwork as a value: 'ShelbyNetwork' only refers to a type, but is being used as a value here. This forces developers to cast it as string/any (network: "shelbynet" as any).
2. Calling ShelbyRPCClient.putBlob directly without prior on-chain commitments results in a confusing generic HTTP 404 error from the RPC Node, which might make developers think the RPC endpoint is down or incorrect:
   {"message":"not found","error_code":"web_framework_error","vm_error_code":null}

Logs / Screenshots

// test.ts (Snippet demonstrating the issues)

import { Aptos, AptosConfig, Network, Account } from "@aptos-labs/ts-sdk";
import { ShelbyClient, ShelbyNetwork } from "@shelby-protocol/sdk/node";

async function runTests() {
  // 🐛 DX Issue 1: ShelbyNetwork type forcing "as any" or "as ShelbyNetwork"
  // Using ShelbyNetwork.Devnet directly throws: 
  // TS2693: 'ShelbyNetwork' only refers to a type, but is being used as a value here.
  const shelby = new ShelbyClient({
      network: "shelbynet" as any, 
      rpc: { baseUrl: "https://api.shelbynet.shelby.xyz" }
  });

  const dummyBuffer = new Uint8Array(Buffer.from("Test Data", "utf-8"));
  const account = Account.generate();

  // 🐛 DX Issue 2: putBlob returns confusing 404 if no prior blockchain commitments exist
  try {
      // Assuming a developer tries to use ShelbyRPCClient standalone:
      // await shelbyRPC.putBlob({ ... }); 
      
      // Expected Error: "Blob commitments not found on Aptos chain"
      // Actual Error Received:
      // Error: Failed to start multipart upload! status: 404, body: {"message":"not found","error_code":"web_framework_error","vm_error_code":null}
  } catch(e) {
      console.error(e);
  }
}

Contact (Optional)

https://github.com/adityaypz

Pre-Checks

• I've searched existing issues
• This is not a security vulnerability (see SECURITY.md)