Save an artifact to storage.
Stores user-created content (diagrams, notes, code) in an organized
file structure. Content is also indexed for search.
Args:
content: File content to save
path: Full path including filename (e.g., "/project/docs/api.md")
Returns:
Success message or error description
Examples:
>>> await save_artifact("# README", "/readme.md")
"✅ Artifact saved: /readme.md (8 bytes)"
>>> await save_artifact("<svg>...</svg>", "/diagrams/architecture.svg")
"✅ Artifact saved: /diagrams/architecture.svg (image/svg+xml, 45 bytes)"