fix: ensure output directory exists before writing in flow template (#5291)

The `save_content` method wrote to `output/post.md` without ensuring the
`output/` directory exists, causing a FileNotFoundError when the directory
hasn't been created by another step.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/crewai/src/crewai/cli/templates/flow/main.py

@@ -1,4 +1,6 @@
 #!/usr/bin/env python
+from pathlib import Path
+
 from pydantic import BaseModel
 
 from crewai.flow import Flow, listen, start
@@ -42,7 +44,9 @@ class ContentFlow(Flow[ContentState]):
     @listen(generate_content)
     def save_content(self):
         print("Saving content")
-        with open("output/post.md", "w") as f:
+        output_dir = Path("output")
+        output_dir.mkdir(exist_ok=True)
+        with open(output_dir / "post.md", "w") as f:
             f.write(self.state.final_post)
         print("Post saved to output/post.md")