Fix flaky integration tests and UI test runner robustness

- Skip Invidious integration tests gracefully on .noConnection so a
  transient instance outage no longer fails CI
- Point integration tests at i01.v.yattee.stream (the previous test
  instance was decommissioned)
- Force UTF-8 on AXe CLI output in the UI test wrapper; ASCII-tagged
  bytes were crashing JSON.parse in describe_ui
- Add iOS 26.4 visual baselines for app-launch-home and settings-main

spec/ui/support/axe.rb

@@ -156,6 +156,7 @@ module UITest
     # @param text [String] Text to type
     def type(text)
       output, status = Open3.capture2e('axe', 'type', '--stdin', '--udid', @udid, stdin_data: text)
+      output = output.dup.force_encoding('UTF-8') if output.is_a?(String)
       raise AxeError, "type failed: #{output}" unless status.success?
     end
 
@@ -201,7 +202,9 @@ module UITest
     private
 
     def run_axe(*)
-      Open3.capture2e('axe', *, '--udid', @udid)
+      output, status = Open3.capture2e('axe', *, '--udid', @udid)
+      output = output.dup.force_encoding('UTF-8') if output.is_a?(String)
+      [output, status]
     end
 
     # Wait for a file to exist and have non-zero size