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/package-lock.json

@@ -9,6 +9,7 @@
       "version": "0.0.0",
       "dependencies": {
         "@popperjs/core": "^2.11.8",
+        "@wailsio/runtime": "3.0.0-beta.20",
         "flowbite": "^2.5.1",
         "flowbite-svelte": "^0.46.16",
         "moment": "^2.30.1"
@@ -651,6 +652,12 @@
       "integrity": "sha512-60BCwRFOZCQhDncwQdxxeOEEkbc5dIMccYLwbxsS4TUNeVECQ/pBJ0j09mrHOl/JJvpRPGwO9SvE4nR2Nb/a4Q==",
       "license": "MIT"
     },
+    "node_modules/@wailsio/runtime": {
+      "version": "3.0.0-beta.20",
+      "resolved": "https://registry.npmjs.org/@wailsio/runtime/-/runtime-3.0.0-beta.20.tgz",
+      "integrity": "sha512-oPpWBgNK4QISP9/AweVnRIBg6hlEP7HVi0i4gVl0+6JEsQ6vDDTJXmbyy/j6AITPHWq7cWOYl2Ey5uucl1u3hw==",
+      "license": "MIT"
+    },
     "node_modules/@yr/monotone-cubic-spline": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/@yr/monotone-cubic-spline/-/monotone-cubic-spline-1.0.3.tgz",