Add a reusable DID provider helper for offline-first workflows

Proposed feature

add a reusable DID provider helper for offline-first workflows

Summary

Add a small reusable helper module for PRISM DID creation in the TypeScript SDK. This is a beginner-friendly step toward the mentorship project’s offline-first SSI dashboard.

Motivation

The mentorship project needs a reusable DID creation flow that can work in the browser and support future Cardano / CIP-30 publishing. A small DID helper is a good first contribution because it:

• reuses the existing SDK building blocks
• fits the offline-first architecture
• can be tested independently
• can later be used by the web dashboard and other apps

Files to Add / Update

• packages/lib/sdk/src/modules/did-provider.ts
• packages/lib/sdk/tests/modules/did-provider.test.ts
• packages/lib/sdk/src/index.ts

Acceptance Criteria

• A reusable createPrismDID() helper exists
• The helper uses the SDK’s local Apollo/Castor implementation
• A unit test covers the helper
• The helper is exported from the package entry point
• The code compiles with the SDK typecheck

Notes

This should stay small and beginner-friendly. Avoid adding UI work or Cardano publishing logic in this task; those can come later.

Feature description

Proposed Change

Add a helper module that:

• creates a PRISM DID using the SDK’s Apollo + Castor layers
• supports a deterministic seed for testing
• returns the DID, short-form DID, and private key information
• is exported from the main SDK entry point

Anything else?

No response

Start by reading the existing Apollo and Castor SDK building blocks, then inspect packages/lib/sdk/src/modules/did-provider.ts and the package entry point at packages/lib/sdk/src/index.ts. Add the reusable createPrismDID() helper and its test in packages/lib/sdk/tests/modules/did-provider.test.ts; done means the helper supports deterministic seeds, returns the specified DID and key information, is exported, and passes the SDK typecheck.