feat: offload reconstruction parsing to a background thread via react-native-worklets-core

[Copilot]

Synchronous parseReconstruction runs on the main JS thread after every solve, blocking the UI — most noticeably on gyroscope-equipped smartcubes with dense BLE event streams.

Approach

Introduce react-native-worklets-core to run reconstruction parsing on a dedicated JSI background thread, letting the UI transition immediately while the CPU-intensive solution-analyzer work completes asynchronously.

Changes

• parseReconstructionAsync.ts (new) — creates a named ReconstructionContext worklet and wraps parseReconstruction in a Promise; errors forwarded via runOnJS(reject)
• 'worklet' directives — added to parseReconstruction, parseTimestampedMoves, compressDoubleTurns, reconstructionFor, and __reconstructionFor so the Babel plugin serializes the full call chain for background execution
• PracticeView.tsx — handleSolveComplete refactored to useCallback:
  1. Remove BLE subscriptions and snapshot recordings synchronously
  2. Call setTimerState(TimerState.SCRAMBLING) immediately (zero UI lag)
  3. Parse reconstructions and persist the attempt in the background via Promise.all + .catch
• babel.config.js — react-native-worklets-core/plugin added before the Reanimated plugin
• globalMock.js — Jest mock for react-native-worklets-core (runAsync executes synchronously via Promise.resolve)

// Before: blocks the UI until reconstruction finishes
function handleSolveComplete() {
  const attempt = assembleAttempt(); // ← parseReconstruction runs here, on main thread
  persistAttempt(attempt);
  nextTimerState();                  // ← UI only updates after parsing completes
}

// After: UI transitions instantly; parsing runs in background
const handleSolveComplete = useCallback(() => {
  // ... stop BLE, snapshot recordings ...
  setTimerState(TimerState.SCRAMBLING);          // immediate
  Promise.all(wipSolutions.map(async wip => {
    const reconstruction = await parseReconstructionAsync(...); // background thread
    // ...
  })).then(persistAttempt).catch(console.error); // async, non-blocking
}, [...]);

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• static.realm.io
  • Triggering command: /opt/hostedtoolcache/node/24.14.0/x64/bin/node /opt/hostedtoolcache/node/24.14.0/x64/bin/node /home/REDACTED/work/speedcuber-timer/speedcuber-timer/node_modules/realm/node_modules/.bin/prebuild-install --runtime napi (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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