Replace UI DispatcherTimer polling with a StudySnapshotRenderGate across multiple widgets to queue and apply only the latest analytics snapshot; components updated include StudyDeductionReasonsWidget, StudyEnvironmentWidget, StudyInterruptDensityWidget, StudyNoiseCurveWidget. Add StudySnapshotRenderGate implementation to coordinate rendering and monitoring leases and update subscription/lease lifecycle handling (subscribe/unsubscribe, Acquire/Dispose leases, Clear/Dispose gate). Rewrite chart controls (StudyNoiseCurveChartControl and StudyNoiseDistributionScatterChartControl) to use stable logical-time origins, split series into static vs dynamic tails, add geometry/sample caching, stable jitter/coordinate mapping helpers, and expose internal helpers & counts for testing. Add unit tests (StudyComponentRenderingTests) covering the render gate and chart behaviors (layer counts, logical X mapping, stable jitter, cache rebuild). These changes improve rendering correctness and performance by avoiding redundant renders and enabling deterministic chart layout.
Introduce a new update subsystem: shared contracts for manifests, messages, paths and state (LanMountainDesktop.Shared.Contracts.Update). Add IPC and reporting infrastructure for installer progress (IUpdateProgressReporter, LauncherUpdateProgressIpcServer, NullUpdateProgressReporter) and integrate progress/complete reporting into UpdateEngineService. Add multiple update service components and providers (CompositeManifestProvider, GithubReleaseManifestProvider, PlondsApiManifestProvider, UpdateDownloadEngine, UpdateOrchestrator, UpdateInstallGateway, CLI launcher bridge, launcher bridge interfaces, observable helper, state store, progress subject, JSON context). Update settings and models to support UseGhProxyMirror and PLONDS/GitHub fallback logic, plus localization strings and UI/viewmodel files for update settings and progress. Misc: installer script tweak and a small change in Plonds generator. This adds end-to-end support for checking, downloading and reporting update progress and results.
