Add doRequest() and doJSON() methods for hub API communication. doRequest
builds full URLs, sets bearer auth and JSON headers, tracks connected
state. doJSON handles status codes: 401 unauthorised, 409 ConflictError,
404 NotFoundError, and generic errors for other 4xx/5xx responses.
Co-Authored-By: Virgil <virgil@lethean.io>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Introduce HubService struct with types for hub coordination: PendingOp,
HubClaim, LeaderboardEntry, GlobalStats, ConflictError, NotFoundError.
Constructor generates a crypto/rand client ID when none exists. Includes
no-op loadPendingOps/savePendingOps stubs for future persistence.
Co-Authored-By: Virgil <virgil@lethean.io>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
