Add SourceTexts and PluralForm fields to translation DTOs

- Add SourceTexts dictionary to TranslateRequestDto for UI edits
- Add PluralForm field to TranslationResultDto for plural key support

Author: nickprotop

cloud/src/LrmCloud.Shared/DTOs/Translation/TranslateRequestDto.cs

@@ -12,6 +12,13 @@ public class TranslateRequestDto
     /// </summary>
     public List<string> Keys { get; set; } = new();
 
+    /// <summary>
+    /// Optional source texts for each key. When provided, these values are used instead of
+    /// the saved database values. This allows translating unsaved edits from the UI.
+    /// Key = key name (for non-plural) or "keyName:pluralForm" (for plural), Value = source text to translate.
+    /// </summary>
+    public Dictionary<string, string>? SourceTexts { get; set; }
+
     /// <summary>
     /// Target language codes to translate to.
     /// </summary>

cloud/src/LrmCloud.Shared/DTOs/Translation/TranslateResponseDto.cs

@@ -66,6 +66,11 @@ public class TranslationResultDto
     /// </summary>
     public string TargetLanguage { get; set; } = string.Empty;
 
+    /// <summary>
+    /// Plural form (e.g., "one", "other"). Empty for non-plural keys.
+    /// </summary>
+    public string PluralForm { get; set; } = string.Empty;
+
     /// <summary>
     /// Original source text.
     /// </summary>