chore(flow): expand host-return whitelist and add a DEBUG host bundle probe

- Rebuild the return-to-host whitelist from the CN/US top charts plus Apple
  system apps; drop the canOpenURL pre-check (LSApplicationQueriesSchemes
  is capped at 50) and let open() report failure.
- Never record an OSG bundle id as the host to return to.
- DEBUG only: probe the host bundle id through the keyboard arbiter
  callback and surface the log on a Home test card. Release builds keep
  the previous behaviour (no host identification).

project.yml

@@ -353,6 +353,7 @@ targets:
     settings:
       base:
         PRODUCT_BUNDLE_IDENTIFIER: com.osgkeyboard.ios.keyboard
+        SWIFT_OBJC_BRIDGING_HEADER: OSGKeyboardExt/OSGKeyboardExt-Bridging-Header.h
         TARGETED_DEVICE_FAMILY: "1,2"
         SUPPORTS_MACCATALYST: NO
         SUPPORTS_MAC_DESIGNED_FOR_IPHONE_IPAD: NO