Fix custom configuration server metadata

[eliotcougar]

Summary

Custom configs using legacy vnext/servers settings lost their displayed endpoint when parsing switched to a DTO that no longer retained those fields. Read display metadata directly from the raw JSON, covering legacy arrays, flat settings, and WireGuard peers.

• Show the existing masked endpoint only when there is exactly one server with a valid address.
• Show Multiple Servers for multiple server entries, with translations in all nine supported locales.
• Refresh metadata for existing saved custom profiles during background loading, preserving the original JSON and regenerating the searchable description from the current endpoint.

Related to #6233 (custom-config parser).

Validation

• 99 JVM tests passed, including 18 parser and row-model regression tests.
• Play Store debug and release builds passed; packaged native libraries checked for every ABI.
• Emulator checks passed for single/multiple/invalid endpoints, English/Russian/Arabic labels, and cold restart. Packaged translations checked for all nine locales. Port filtering matched the current custom endpoint and excluded its stale saved port.

Not run: physical-device, live proxy connectivity, and TalkBack speech checks; validation used an emulator and UI-tree inspection.