Add Aegis dashboard admin action receipt view

[panditdhamdhere]

Summary

• Add typed admin receipt model and mapper for whitelist, mint, asset registration, and role-change operations.
• Show receipt status, operation type, target, transaction hash, explorer link, and next action.
• Reuse shared TransactionReceipt, mapToTransactionResult, and getExplorerUrl rather than forking a parallel status stack.
• Document receipt limitations for local/mock-only admin actions.

Closes #179

Acceptance criteria

• Admin action receipt view is implemented
• Major admin operations are represented
• Transaction status is displayed
• Explorer link is supported where applicable
• Tests or fixtures cover receipt states
• Docs explain receipt limitations

Test plan

• Add/remove a whitelist address from /admin and confirm the receipt shows status, target, hash, and explorer link
• Run a mint from /admin and verify the receipt offers "Mint another"
• Submit an asset request from /issuer and confirm the local-only limitation note appears with no explorer link
• Trigger a bulk compliance update from /compliance and confirm the local-action limitation is shown
• npm test and npm run build pass