fix: Address PR feedback for structured output fallback

- Throw error immediately when JSON extraction fails in
  generate-features-from-spec.ts to avoid redundant parsing attempt
  (feedback from Gemini Code Assist review)
- Emit spec_regeneration_error event before throwing for consistency
- Fix TypeScript cast in sync-spec.ts by using double cast through unknown

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/server/src/routes/app-spec/generate-features-from-spec.ts

@@ -286,9 +286,20 @@ Your entire response should be valid JSON starting with { and ending with }. No
       contentForParsing = JSON.stringify(extracted);
       logger.info('✅ Pre-extracted JSON from text response');
     } else {
-      // Fall back to raw text (let parseAndCreateFeatures try its extraction)
-      contentForParsing = rawText;
-      logger.warn('⚠️ Could not pre-extract JSON, passing raw text to parser');
+      // If pre-extraction fails, we know the next step will also fail.
+      // Throw an error here to avoid redundant parsing and make the failure point clearer.
+      logger.error(
+        '❌ Could not extract features JSON from model response. Full response text was:\n' +
+          rawText
+      );
+      const errorMessage =
+        'Failed to parse features from model response: No valid JSON with a "features" array found.';
+      events.emit('spec-regeneration:event', {
+        type: 'spec_regeneration_error',
+        error: errorMessage,
+        projectPath: projectPath,
+      });
+      throw new Error(errorMessage);
     }
   }
 

apps/server/src/routes/app-spec/sync-spec.ts

@@ -261,7 +261,7 @@ CRITICAL INSTRUCTIONS:
 
     if (techResult.structured_output) {
       // Use structured output from Claude/Codex models
-      const structured = techResult.structured_output as TechStackExtractionResult;
+      const structured = techResult.structured_output as unknown as TechStackExtractionResult;
       if (Array.isArray(structured.technologies)) {
         parsedTechnologies = structured.technologies;
         logger.info('✅ Received structured output for tech analysis');