Add native iOS client with FileBrowser support

[suyun888]

What changed

• add a native SwiftUI iOS 17+ client and generated Xcode project
• add secure Keychain configuration, health/system/storage/UPS details, Docker operations, logs and live stats
• add read-only VM status, operation history, appearance and refresh controls
• add automatic FileBrowser 2.x and compatible XFileManager detection with native browse, preview, upload, rename, delete, download and share workflows
• include the validated unsigned UnraidManager-0.3.0-unsigned.ipa for self-signing

Why

The repository previously provided only an Android client. The original file workflow expected an unpublished XFileManager-compatible service; FileBrowser compatibility lets the iOS client work with the maintained official FileBrowser container already available on Unraid.

Validation

• Xcode 26.6 Release build against the iOS 26.5 device SDK
• arm64 Mach-O output with minimum iOS 17.0
• live FileBrowser 2.63.18 API checks for login, listing, folder creation, upload, rename, sharing and deletion
• unsigned IPA archive integrity verified with unzip -t
• bundle version 0.3.0 (build 3), ATS/local-network permissions and compiled AppIcon assets verified
• SHA-256: 402721fb9cf93c79202c2d7ed4bea676c60ec3ddd6285323a6bac168f3bcf722