Add Fallback from LocalizedEnumTextAttribute to EnumTextAttribute

[dparvin]

✨ Feature Request: Fallback from LocalizedEnumTextAttribute → EnumTextAttribute

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Overview

Provide a graceful fallback so that when a localized string is not found, the value from an accompanying
EnumTextAttribute is used instead.
This enables incremental migration from static enum labels to fully‑localized strings without breaking the UI.

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Proposed Flow

1. Localized string found → return it.
2. Localized string missing
   • Debug mode ON → return a diagnostic placeholder
     [[Namespace.ResourceKey]]
   • Debug mode OFF →
     • If the enum field has an EnumTextAttribute, return its Text.
     • Otherwise fall back to the raw enum name.

┌───────────┐
│  Exists?  │── Yes ──► return localized
└────┬──────┘
     No
     │
     ▼
┌───────────┐  debug?
│ Debug ON? │── Yes ──► [[ResourcePath::Key]]
└────┬──────┘
     No
     │
     ▼
┌────────────────────────────┐
│ EnumTextAttribute present? │── Yes ──► return EnumText.Text
└────┬───────────────────────┘
     No
     │
     ▼
return enum name

Benefits

• Incremental migration – keep existing EnumText values until resource strings are ready.
• No UI regressions – end‑users never see raw resource keys.
• Debug visibility – missing keys stand out in debug builds.
• Easy cleanup – once all keys are localized, remove obsolete EnumText attributes.

Implementation Notes

• Logic can live inside LocalizedEnumTextAttribute.GetLocalizedText() or a helper like Support.GetEnumDisplayText(...).
• Throw ArgumentException on ResourceUsage.None (consistent with other helpers).
• Add comprehensive unit tests covering:
  • localized found
  • debug placeholder
  • EnumText fallback
  • final enum‑name fallback.