Use OpenTelemetry enduser.id attribute for Langfuse user tracking

- Remove broken Langfuse SDK trace() call (method doesn't exist)
- Add user_id via OpenTelemetry semantic convention 'enduser.id'
- Langfuse will automatically extract user info from OTLP spans
- Cleaner, standards-based approach using OTLP exclusively
- Fixes AttributeError: 'Langfuse' object has no attribute 'trace'

Signed-off-by: sallyom <somalley@redhat.com>

Author: sallyom

components/runners/claude-code-runner/wrapper.py

@@ -191,9 +191,14 @@ async def run(self):
     async def _run_claude_agent_sdk(self, prompt: str):
         """Execute the Claude Code SDK with the given prompt."""
         try:
+            # Extract user context for observability (will be added to OTLP spans)
+            user_id = os.getenv('USER_ID', '').strip()
+            user_name = os.getenv('USER_NAME', '').strip()
+
             # Initialize Langfuse for observability if configured
             langfuse_client = None
             langfuse_session_span = None
+            langfuse_enabled = False
             if LANGFUSE_AVAILABLE:
                 langfuse_enabled = os.getenv('LANGFUSE_ENABLED', '').strip().lower() in ('1', 'true', 'yes')
                 if langfuse_enabled:
@@ -204,33 +209,15 @@ async def _run_claude_agent_sdk(self, prompt: str):
                             host=os.getenv('LANGFUSE_HOST')
                         )
 
-                        # Extract user context for observability
-                        user_id = os.getenv('USER_ID', '').strip()
-                        user_name = os.getenv('USER_NAME', '').strip()
-
-                        # Create a trace for this session with userId (Langfuse SDK 3.x)
-                        # Pass user_id directly to trace() for proper user tracking
-                        langfuse_session_span = langfuse_client.trace(
-                            name="claude_agent_session",
-                            input={"prompt": prompt},
-                            user_id=user_id if user_id else None,
-                            metadata={
-                                "session_id": self.context.session_id,
-                                "namespace": self.context.get_env('AGENTIC_SESSION_NAMESPACE', 'unknown'),
-                                "user_name": user_name if user_name else None,
-                            },
-                        )
-
                         if user_id:
-                            logging.info(f"Langfuse: Tracking session for user {user_name} ({user_id})")
+                            logging.info(f"Langfuse: User context available for user {user_name} ({user_id})")
 
-                        logging.info(f"Langfuse tracing enabled for session")
+                        logging.info(f"Langfuse client initialized (user tracking via OTLP)")
                     except Exception as e:
-                        logging.warning(f"Failed to initialize Langfuse: {e}")
+                        logging.warning(f"Failed to initialize Langfuse client: {e}")
                         import traceback
                         logging.warning(traceback.format_exc())
                         langfuse_client = None
-                        langfuse_session_span = None
 
             # Initialize OpenTelemetry for distributed tracing
             # Can send to Langfuse OTLP endpoint OR separate OTEL Collector
@@ -299,14 +286,26 @@ async def _run_claude_agent_sdk(self, prompt: str):
                         # Get tracer (works whether we just set it or it was already set)
                         otel_tracer = trace.get_tracer(__name__)
 
-                        # Start session span
+                        # Start session span with user tracking
+                        # Use OpenTelemetry semantic convention 'enduser.id' for user tracking
+                        # Langfuse will automatically extract this from OTLP spans
+                        span_attributes = {
+                            "session.id": self.context.session_id,
+                            "namespace": self.context.get_env('AGENTIC_SESSION_NAMESPACE', 'unknown'),
+                            "prompt.length": len(prompt),
+                        }
+
+                        # Add user attributes if available (OpenTelemetry semantic conventions)
+                        if user_id:
+                            span_attributes["enduser.id"] = user_id
+                            logging.info(f"OTLP: Adding user tracking for {user_name} ({user_id})")
+                        if user_name:
+                            # Not a standard OTEL attribute, but Langfuse may recognize it
+                            span_attributes["user.name"] = user_name
+
                         otel_span = otel_tracer.start_span(
                             "claude_agent_session",
-                            attributes={
-                                "session.id": self.context.session_id,
-                                "namespace": self.context.get_env('AGENTIC_SESSION_NAMESPACE', 'unknown'),
-                                "prompt.length": len(prompt),
-                            }
+                            attributes=span_attributes
                         )
 
                         logging.info(f"OpenTelemetry tracing enabled (endpoint: {otel_endpoint})")