feat(trackers): show a QR code in every tracker sign-in dialog and fit them on TV screens

Every tracker auth dialog (Trakt/Simkl/MDBList device-code and MAL/AniList
OAuth proxy) now shares the same PendingAuthDialog affordances: a QR code for
the sign-in URL, a large copyable URL with the scheme stripped, the browser
launch button (hidden on Apple TV, which has no browser), and the polling
spinner. On wide viewports (TV logical 960x540, desktop, phone landscape) the
QR pane sits beside the instructions so the dialog no longer clips on tvOS,
and the content is scrollable as an overflow safety net. Device activation
codes scale down instead of wrapping.

lib/i18n/de.i18n.json

@@ -1868,7 +1868,7 @@
     },
     "deviceCode": {
       "title": "Plezy auf ${service} aktivieren",
-      "body": "Gehe zu ${url} und gib diesen Code ein:",
+      "instructions": "",
       "openToActivate": "${service} zum Aktivieren öffnen",
       "copyCode": "Aktivierungscode kopieren",
       "waitingForAuthorization": "Warte auf Autorisierung…",
@@ -1877,7 +1877,9 @@
     "oauthProxy": {
       "title": "Bei ${service} anmelden",
       "body": "Scanne diesen QR-Code oder öffne die URL auf einem beliebigen Gerät.",
-      "openToSignIn": "${service} zum Anmelden öffnen",
+      "openToSignIn": "${service} zum Anmelden öffnen"
+    },
+    "pendingAuth": {
       "copyUrl": "Anmelde-URL kopieren",
       "urlCopied": "URL kopiert"
     },