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 localStorage persistence and example/docs updates; no production WalletKit or auth path changes.

Overview
The Next.js examples/web demo no longer throws away identity on every reload: it persists a versioned demo profile in localStorage (storageId, databaseKey, seed, and registration/issuance flags) and passes the saved storageId and key into initializeWalletKit() so encrypted OPFS SQLite can be reopened after refresh.

demo-profile.ts validates stored JSON (version, key shapes, progress consistency) and fails closed on corrupt or unsupported profiles instead of silently rotating keys. page.tsx restores UI gating from saved progress, updates the profile when registering, issuing, or deriving a new seed, and requires authenticator initialization before proof generation. Four bun test cases cover persistence and error paths; docs and root README point at examples/web and call out staging-only raw key retention.

The example package is renamed to walletkit-web-example; changes are limited to the demo and documentation.

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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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