fix(blocks): Update AIConditionBlock error output to follow system pattern

- Changed field name from 'error_message' to 'error' exactly
- Removed default value from error field (system behavior)
- Modified run method to yield 'error' only when errors occur
- Updated test_output to match new behavior

This aligns with the standard error handling pattern used by other blocks
in the platform where error outputs have no default and are yielded
conditionally.

Co-authored-by: Nicholas Tindle <ntindle@users.noreply.github.com>

autogpt_platform/backend/backend/blocks/ai_condition.py

@@ -60,9 +60,8 @@ class AIConditionBlock(AIBlockBase):
         no_output: Any = SchemaField(
             description="The output value if the condition is false"
         )
-        error_message: str = SchemaField(
-            description="Error message if the AI evaluation is uncertain or fails",
-            default="",
+        error: str = SchemaField(
+            description="Error message if the AI evaluation is uncertain or fails"
         )
 
     def __init__(self):
@@ -84,7 +83,6 @@ class AIConditionBlock(AIBlockBase):
             test_output=[
                 ("result", True),
                 ("yes_output", "Valid email"),
-                ("error_message", ""),
             ],
             test_mock={
                 "llm_call": lambda *args, **kwargs: LLMResponse(
@@ -135,7 +133,6 @@ class AIConditionBlock(AIBlockBase):
 
         # Convert input_value to string for AI evaluation
         input_str = str(input_data.input_value)
-        error_message = ""  # Track error messages
 
         # Create the prompt for AI evaluation
         prompt = [
@@ -185,9 +182,9 @@ class AIConditionBlock(AIBlockBase):
                 elif tokens == {"false"} or tokens == {"no"} or tokens == {"0"}:
                     result = False
                 else:
-                    # Unclear or conflicting response - default to False and set error
+                    # Unclear or conflicting response - default to False and yield error
                     result = False
-                    error_message = f"Unclear AI response: '{response.response}'"
+                    yield "error", f"Unclear AI response: '{response.response}'"
 
             # Update internal stats
             self.merge_stats(
@@ -201,12 +198,12 @@ class AIConditionBlock(AIBlockBase):
         except Exception as e:
             # In case of any error, default to False to be safe
             result = False
-            error_message = f"AI evaluation failed: {str(e)}"
             # Log the error but don't fail the block execution
             import logging
 
             logger = logging.getLogger(__name__)
             logger.error(f"AI condition evaluation failed: {str(e)}")
+            yield "error", f"AI evaluation failed: {str(e)}"
 
         # Yield results
         yield "result", result
@@ -215,6 +212,3 @@ class AIConditionBlock(AIBlockBase):
             yield "yes_output", yes_value
         else:
             yield "no_output", no_value
-
-        # Always yield error_message (empty string if no error)
-        yield "error_message", error_message