Minimal-structure migration to Wails v3.0.0-beta.20 (CLI-matching pin). Single App service preserved; no domain logic touched.
- main.go: wails.Run(options.App) -> application.New + RegisterService + Window.NewWithOptions. Window keeps title-with-version, 1024x768, RGBA background, Linux icon/translucency/GpuPolicyNever, ProgramName. SingleInstanceLock -> SingleInstanceOptions (same UniqueID); callback closes over the service variable set right after New.
- app.go: App holds *application.App instead of a context. startup(ctx) is gone; the version title moves into the window options via appTitle(). onSecondInstanceLaunch takes v3 SecondInstanceData (Args/WorkingDir) and uses Window.Current() Restore+Focus plus Event.Emit for launchArgs. ShowVersion uses Dialog.Info.
- AniList/MAL/Simkl *UserFunctions.go: runtime.BrowserOpenURL -> app.Browser.OpenURL (errors logged), runtime.MessageDialog -> app.Dialog.Info chains. OAuth callback servers, token flows, and key names unchanged.
- Secrets: 99designs/keyring replaced with zalando/go-keyring (what v3 itself depends on) under the same AniTrack service name, so existing stored tokens keep working. Per-file Set helpers kept; Open/Ready boilerplate deleted (zalando needs no handle).
- go.mod: v2 + 99designs dropped (stale v2 replace directive removed), v3 beta.20 + zalando v0.2.8 added.