chore(wailsv3): migrate frontend to v3 bindings and runtime

Regenerated bindings with wails3 generate bindings (1 service, 29 methods, 25 models) into frontend/bindings/AniTrack as TypeScript; output verified byte-deterministic across regens, so it is committed like wailsjs was.

- 10 Svelte files: wailsjs/go/main/App imports -> import {App} from bindings/AniTrack with App.* call prefixes. No logic or markup changes.
- WebsiteLink.svelte: BrowserOpenURL -> Browser.OpenURL from @wailsio/runtime.
- AvatarMenu.svelte: runtime.Quit -> Application.Quit from @wailsio/runtime.
- package.json: add @wailsio/runtime pinned to 3.0.0-beta.20 (exact, matching the Go framework); lockfile updated, all deps still max in-range, majors deferred.
- Production vite build passes with the new bindings.

frontend/bindings/github.com/wailsapp/wails/v3/internal/eventcreate.ts

@@ -0,0 +1,9 @@
+//@ts-check
+// Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
+// This file is automatically generated. DO NOT EDIT
+
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-ignore: Unused imports
+import { Create as $Create } from "@wailsio/runtime";
+
+Object.freeze($Create.Events);

frontend/bindings/github.com/wailsapp/wails/v3/internal/eventdata.d.ts

@@ -0,0 +1,2 @@
+// Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
+// This file is automatically generated. DO NOT EDIT