Use language-specific AI prompts instead of wildcard substitution

Refactored the AI prompt system to use proper language-specific prompts (en and ro) instead of a single wildcard prompt with runtime {{languageName}} placeholder substitution.

Benefits:
- Language-specific instructions optimized for each language
- Better control over LLM behavior per language
- Cleaner code without placeholder substitution
- Easier to maintain and update prompts per language

Changes:
- Updated cvMatcher InitialSchema migration to seed en and ro prompts separately
- Modified CvMatcherService to retrieve language-specific prompts directly
- Removed LanguageName() helper method (no longer needed)
- Added fallback prompts in service for safety

The English and Romanian prompts now include specific JSON examples in their respective languages, ensuring the LLM understands the expected output format for each language variant.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Apis/cv-matcher-api/Services/CvMatcherService.cs

@@ -123,11 +123,11 @@ public sealed class CvMatcherService : ICvMatcherService
         var cvText = Limit(cv.Text, 18000);
         var jobText = Limit(job.Text, 14000);
         var evidence = evidenceChunks.Count > 0 ? string.Join("\n\n", evidenceChunks.Take(4)) : Limit(job.Text, 4000);
-        var languageName = LanguageName(language);
 
-        var promptTemplate = await _aiPrompts.GetAsync("ai.cv-match.system-prompt", "*", ct)
-            ?? "You are a strict CV-to-job matching engine. Return JSON only.";
-        var systemPrompt = promptTemplate.Replace("{{languageName}}", languageName, StringComparison.OrdinalIgnoreCase);
+        var systemPrompt = await _aiPrompts.GetAsync("ai.cv-match.system-prompt", language, ct)
+            ?? (language == "ro"
+                ? "Ești un motor strict de potrivire CV-job. Returnează doar JSON. Punctează realist între 0 și 100."
+                : "You are a strict CV-to-job matching engine. Return JSON only. Score realistically from 0 to 100.");
 
         var userPrompt = $"""
             CV:
@@ -195,14 +195,6 @@ public sealed class CvMatcherService : ICvMatcherService
     private static string NormalizeLanguage(string? language) =>
         string.IsNullOrWhiteSpace(language) ? "en" : language.ToLowerInvariant().Split('-')[0].Trim();
 
-    /// <summary>Maps a language code to its full English name for use in the LLM system prompt.</summary>
-    private static string LanguageName(string language) => language switch
-    {
-        "ro" => "Romanian",
-        "en" => "English",
-        _ => "English"
-    };
-
     /// <summary>Truncates <paramref name="value"/> to at most <paramref name="max"/> characters.</summary>
     private static string Limit(string value, int max) => value.Length <= max ? value : value[..max];
 }