Emit user.category for Last9 dashboard compatibility

When metadata.category is provided to @observe(), automatically emit
it as both metadata.category and user.category attributes. The Last9
dashboard LLM page specifically looks for user.category to populate
the Category column and filter dropdown.

This allows users to simply use metadata={"category": "support"} and
have it work correctly in the Last9 UI without needing to know the
platform-specific attribute name.

Also ignore send_test_spans.py in .gitignore.

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

Author: prathamesh-sonpatki

.gitignore

@@ -68,3 +68,4 @@ dmyp.json
 # Claude Code
 .claude/
 test_telemetry.py
+send_test_spans.py

last9_genai/decorators.py

@@ -162,6 +162,10 @@ def _observe_sync(
                 for key, value in metadata.items():
                     span.set_attribute(f"metadata.{key}", str(value))
 
+                # Special handling: emit metadata.category as user.category for Last9 dashboard
+                if "category" in metadata:
+                    span.set_attribute("user.category", str(metadata["category"]))
+
             # Capture function arguments
             if capture_args:
                 _add_function_arguments(span, func, args, kwargs)
@@ -239,6 +243,10 @@ async def _observe_async(
                 for key, value in metadata.items():
                     span.set_attribute(f"metadata.{key}", str(value))
 
+                # Special handling: emit metadata.category as user.category for Last9 dashboard
+                if "category" in metadata:
+                    span.set_attribute("user.category", str(metadata["category"]))
+
             # Capture function arguments
             if capture_args:
                 _add_function_arguments(span, func, args, kwargs)