feat(05-01): update Pipeline to use configurable intermediate directory

- Change default output_dir from cwd to settings.intermediate_path
- Reorder settings initialization before output_dir assignment
- Maintain output_dir parameter for testing/custom override

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

kb_pipeline/pipeline.py

@@ -59,8 +59,8 @@ class Pipeline:
         """
         self.processors: Dict[str, BaseProcessor] = {p.STEP_NAME: p for p in processors}
         self.config = config or PipelineConfig()
-        self.output_dir = output_dir or Path.cwd()
         self.settings = get_settings()
+        self.output_dir = output_dir or Path(self.settings.intermediate_path)
 
         # Validate processors - each processor's STEP_NAME must be in config.steps
         for step_name in self.processors: