Clamp AI summarize lengths for CV rewrite

JobTrackerApi/Services/SummarizerService.cs

@@ -76,6 +76,10 @@ namespace JobTrackerApi.Services
     public class SummarizerService : ISummarizerService
     {
         private const int AiSummarizeMaxInputChars = 20000;
+        private const int AiServiceMaxSummaryLength = 256;
+        private const int AiServiceMaxMinLength = 180;
+        private const int AiServiceMinSummaryLength = 24;
+        private const int AiServiceMinMinLength = 8;
         private readonly IHttpClientFactory _httpFactory;
         private readonly IMemoryCache _cache;
         private readonly object _metricsLock = new();
@@ -172,7 +176,14 @@ namespace JobTrackerApi.Services
 
         private async Task<string?> SummarizeCoreAsync(string text, int maxLength, int minLength)
         {
-            var key = BuildCacheKey(text, maxLength, minLength);
+            var normalizedMaxLength = Math.Clamp(maxLength, AiServiceMinSummaryLength, AiServiceMaxSummaryLength);
+            var normalizedMinLength = Math.Clamp(minLength, AiServiceMinMinLength, AiServiceMaxMinLength);
+            if (normalizedMinLength >= normalizedMaxLength)
+            {
+                normalizedMinLength = Math.Max(AiServiceMinMinLength, normalizedMaxLength - 1);
+            }
+
+            var key = BuildCacheKey(text, normalizedMaxLength, normalizedMinLength);
             Interlocked.Increment(ref _requests);
 
             if (_cache.TryGetValue<string>(key, out var cached))
@@ -189,7 +200,7 @@ namespace JobTrackerApi.Services
             Interlocked.Increment(ref _cacheMisses);
 
             var client = _httpFactory.CreateClient("ai-service");
-            var payload = JsonSerializer.Serialize(new { text, max_length = maxLength, min_length = minLength });
+            var payload = JsonSerializer.Serialize(new { text, max_length = normalizedMaxLength, min_length = normalizedMinLength });
             using var content = new StringContent(payload, Encoding.UTF8, "application/json");
             var sw = Stopwatch.StartNew();