Persist the browser demo account and storage across reloads

[Dzejkop]

Reopen the same staging demo account and encrypted OPFS databases after a page reload. Previously every load generated a new database key, storage namespace, and seed, leaving the previous databases inaccessible.

• Save a versioned demo profile containing the storage ID, database key, seed, and completed registration/issuance steps before initializing WalletKit.
• Restore that profile on reload and offer explicit authenticator initialization to reopen stored credentials. Proof generation stays disabled until initialization completes.
• Reject malformed profiles without replacing their keys, and retain the active identity if saving a newly derived seed fails.
• Document that this staging demo stores raw keys in localStorage. Passkey PRF unlock remains separate work; use one tab per origin.

Validation: production Next.js build and TypeScript checks pass; four persistence tests pass. A Chrome smoke check verified reload key/identity retention, re-derived identity retention, restored-progress button gating, and corrupt-profile rejection. No staging registration or issuance calls were made.

Stacked above #523. This PR changes only the demo.

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Note

Low Risk
Demo-only example changes with no production WalletKit or auth paths affected; localStorage holds staging keys by design with documented caveats.

Overview
The Next.js uniffi-web-authenticator-poc demo no longer throws away the WalletKit storage ID, database key, and seed on every reload. It adds a versioned demo-profile in localStorage (with validation and fail-closed behavior for corrupt or unsupported versions) and wires page.tsx to restore that profile when calling initializeWalletKit, persist progress after register/issue/derive, and restore UI gating for registration and issuance after reload.

Generate proof now requires the authenticator to be initialized again (not only that a credential was issued). README copy is updated for persistent OPFS reopening and staging-only key retention; bun test covers profile persistence, and test files are excluded from the Next TypeScript build.

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Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

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Failed save leaves profile flags inconsistent

Low Severity

register and issue set saved.registered / saved.credentialIssued on the live profile.current object before saveDemoProfile returns. A failed write leaves memory marked complete while React state and localStorage stay incomplete, so Derive stays enabled and can persist a new seed as already registered.

Additional Locations (1)

• examples/uniffi-web-authenticator-poc/src/app/page.tsx#L135-L137

 

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