fix(ios): drop SwiftUICore autolink on pods so the app links via SwiftUI re-export

Build #9 proved `-weak_framework SwiftUICore` does NOT bypass the allowed-client
check, and applying it to the tvOS app target regressed tvOS — reverted that
plugin (withSwiftUICoreWeakLink).

Confirmed root cause from build #8/#9 logs: both iOS jobs fail at the app
*executable* link (`Ld … Streamyfin`), not at any pod. SwiftUI was split into
SwiftUI + SwiftUICore on iOS 26; the SwiftUI pods emit a `-framework SwiftUICore`
autolink directive that, under use_frameworks :static, is inherited by the app's
static link, and the app isn't an allowed client of the private SwiftUICore.tbd.

Fix: in the pod post_install, compile pods with
`-Xfrontend -disable-autolink-framework -Xfrontend SwiftUICore` so they stop
emitting that direct autolink. SwiftUICore symbols then resolve through SwiftUI's
re-export (SwiftUI.tbd re-exports SwiftUICore). Scoped to phone
(ENV['EXPO_TV'] != '1') to leave the green tvOS build untouched.

Also harden scripts/ios/build-ios.ts: displayBuildError now surfaces the
"Undefined symbols for architecture …" linker block, which the error:-only
pattern filter was swallowing (so unsigned-build failures show the real symbol).

app.json

@@ -133,7 +133,6 @@
       ],
       "expo-web-browser",
       ["./plugins/with-runtime-framework-headers.js"],
-      ["./plugins/withSwiftUICoreWeakLink.js"],
       ["./plugins/withChangeNativeAndroidTextToWhite.js"],
       ["./plugins/withAndroidAlertColors.js"],
       ["./plugins/withAndroidManifest.js"],