Move WalletKit web into a package-owned worker

[Dzejkop]

Make walletkit-web own its Web Worker and expose an async TypeScript facade. Hosts supply a resolved database key and can configure worker/Wasm URLs; generated Rust bindings remain inside the worker.

• Implement the worker protocol, lifecycle, and async public API.
• Update the Next.js demo to use the package worker and databaseKey option. It uses a random in-memory key as a stand-in; passkey acquisition remains host integration work.
• Add browser coverage for worker lifecycle, URL overrides, exclusive pool ownership, persistent direct keys, and wrong-key rejection. The current browser setup supports one WalletKit worker per origin.

Targets #522 directly, above the original POC (#480). The browser uses StorageKeys.fromBytes and does not need a software keystore or envelope blob database.

Validation: Wasm package build (including TypeScript checking and bundling), fixture TypeScript checking, and all 6 Chrome browser tests pass on the rebased stack.

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Note

High Risk
Breaking public API and cryptographic/storage wiring (database keys, OPFS, worker exclusivity); consumers must migrate off raw generated bindings.

Overview
walletkit-web no longer exposes the generated UniFFI namespace. Initialization now requires a 32-byte databaseKey and optional storageId, spins up a package-bundled worker, and returns a WalletKit client with promise-based RPC (register / pollRegistration, initializeAuthenticator, prepareCredential / storeCredential, generateProof, close / terminate). Rust/WASM, SQLite, and OPFS persistence run inside that worker; only plain data crosses the boundary.

The Next.js POC drops its local walletkit.worker.ts and drives the full staging flow from the page via initializeWalletKit, with in-memory keys and updated copy about OPFS persistence after reload.

Tooling/docs: bundle ships walletkit.worker.js, README documents the browser API and storage model, version 0.22.1, plus Playwright + Vite browser tests (lifecycle, exclusive pool, wrong key, URL overrides).

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

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Failed registration cannot be retried

Medium Severity

register refuses a second attempt whenever registration is already set, and pollRegistration never clears that handle after a failed status. A gateway failure therefore makes the client permanently unable to start a new registration, while the demo still offers the Register action because it only sets registered on success.

Additional Locations (1)

• examples/uniffi-web-authenticator-poc/src/app/page.tsx#L72-L84

 

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