feat(search): use native tvOS keyboard

[MagiqueDeveloper]

Summary

• Replace the custom/hidden UIKit search input with real native tvOS TextField controls in both Search styles.
• Keep the existing glass search styling while suppressing tvOS's default white focus platter.
• Preserve the Netflix-style results split, recent searches, type filters, result focus restoration, and details-overlay behavior.
• Remove obsolete custom-keyboard helpers from NetflixSearchViewModel.

Why the native keyboard

The native tvOS keyboard was chosen instead of rebuilding the keyboard in SwiftUI because it is the more intuitive Apple TV experience:

• It uses the keyboard layout users already know from tvOS.
• Siri Remote focus movement, key navigation, editing, suggestions, and dictation remain system-managed.
• Siri Remote hold-to-talk works through the focused search field without adding a separate in-app microphone button.
• Accessibility, localization, keyboard changes, and future tvOS improvements come from the system instead of requiring ongoing custom-keyboard maintenance.
• A custom keyboard would require manually reproducing key layout, focus transitions, text editing, deletion, suggestions, and dictation behavior while being less familiar to users.

The app still owns the visual presentation: the real text field remains focusable and connected to the search view model, while the surrounding glass styling hides the default focus platter and keeps the search page consistent with the rest of the app.

Verification

• xcodebuild ... build succeeded for Apple TV 4K (3rd generation) simulator, tvOS 27.0.
• xcodebuild ... test succeeded: 279 tests, 0 failures.
• The built app was installed and launched on the Apple TV simulator.
• Manual simulator verification confirmed the search interaction works.
• Physical Apple TV dictation verification remains recommended before merge.

Imagery

Closes #55

[MagiqueDeveloper]

This is the basics, I may refine it with more commits.