fix(ai): request structured JSON for queued strategies

JobTrackerApi/Services/StrategySnapshotService.cs

@@ -95,6 +95,7 @@ Candidate master CV:
         var generation = await summarizer.GenerateSectionWithMetadataAsync(
             instruction,
             context,
+            AiGenerationOutputMode.StructuredJson,
             900,
             120,
             cancellationToken);

JobTrackerApi/Services/SummarizerService.cs

@@ -59,7 +59,7 @@ namespace JobTrackerApi.Services
         string? FileName
     );
 
-    public enum AiGenerationOutputMode { Text, CvBlocksJson }
+    public enum AiGenerationOutputMode { Text, CvBlocksJson, StructuredJson }
 
     public sealed record AiGenerationResult(
         string Text,
@@ -232,7 +232,7 @@ namespace JobTrackerApi.Services
         {
             if (outputMode == AiGenerationOutputMode.Text)
                 return GenerateSectionWithMetadataAsync(instruction, text, maxLength, minLength, cancellationToken);
-            if (outputMode != AiGenerationOutputMode.CvBlocksJson || string.IsNullOrWhiteSpace(instruction) || string.IsNullOrWhiteSpace(text))
+            if (outputMode is not (AiGenerationOutputMode.CvBlocksJson or AiGenerationOutputMode.StructuredJson) || string.IsNullOrWhiteSpace(instruction) || string.IsNullOrWhiteSpace(text))
                 return Task.FromResult<AiGenerationResult?>(null);
             return RewriteCoreAsync(instruction.Trim(), text.Trim(), maxLength, minLength, cancellationToken, outputMode);
         }
@@ -328,7 +328,7 @@ namespace JobTrackerApi.Services
                 text,
                 max_length = normalizedMaxLength,
                 min_length = normalizedMinLength,
-                output_mode = outputMode == AiGenerationOutputMode.CvBlocksJson ? "cv_blocks_json" : "text",
+                output_mode = outputMode switch { AiGenerationOutputMode.CvBlocksJson => "cv_blocks_json", AiGenerationOutputMode.StructuredJson => "structured_json", _ => "text" },
             });
             using var content = new StringContent(payload, Encoding.UTF8, "application/json");
             var sw = Stopwatch.StartNew();