fix(pipeline): Merge multiple instruction sets for AI test generation

Author: vishnurajkv

src/secnodeapi/services/pipeline.py

@@ -479,10 +479,17 @@ async def build_pipeline_artifacts(
         logger.warning("Deep recon phase failed, continuing without parameter enrichment", error=str(e))
 
     understanding = await understand_api_with_ai(api_structure, tool_context=tool_context)
+    
+    # Merge all user instructions into a single variables dictionary for the AI
+    combined_instructions = {}
+    if pipeline_input.instructions:
+        for instr in pipeline_input.instructions:
+            combined_instructions.update(instr.variables)
+            
     tests = await generate_test_cases(
         understanding,
         api_structure,
-        instructions=pipeline_input.instructions[0].model_dump() if pipeline_input.instructions else None,
+        instructions={"variables": combined_instructions} if combined_instructions else None,
         tool_context=tool_context,
     )
     return api_structure, tests, orch_result