SIENTIAPDE-1478

Enhance PI Web API Scouter Workflow and Documentation

- Added support for PI Web API data ingestion, including real-time and historical data retrieval.
- Implemented timestamp normalization to ensure consistency across records.
- Updated README.md to reflect new features and detailed workflow execution flow.
- Enhanced API class with comprehensive error handling and cleanup operations.
- Improved CoreScouter workflow with early exit conditions and detailed processing steps.
- Updated configuration parameters for better clarity and usability.

scouter/activities/api.py

@@ -63,6 +63,10 @@ class API(SientiaMonitoring):
     def close(self) -> None:
         """
         Close the PI Web API client and shutdown monitoring services.
+
+        This method performs cleanup operations:
+        - Closes the PI Web API client connection
+        - Shuts down SientiaMonitoring services (metrics, notifications)
         """
         self.pi_web_api_client.close()
         SientiaMonitoring.shutdown(self)
@@ -76,6 +80,11 @@ class API(SientiaMonitoring):
         for a set of configured tags. It returns the data as a list of dictionaries
         suitable for further processing in the workflow.
 
+        The timestamps are normalized to ensure consistency across all records in the
+        response. After converting timestamps to string format, all timestamps are
+        set to the maximum timestamp value (lexicographically) found in the dataset.
+        This ensures all records in a single batch share the same timestamp value.
+
         Args:
             input_data (dict[str, Any]): Activity input parameters.
                 Required fields:
@@ -88,7 +97,7 @@ class API(SientiaMonitoring):
 
         Returns:
             list[dict]: List of data records, each containing:
-                - timestamp: Data point timestamp
+                - timestamp: Normalized timestamp string (all records share the same value)
                 - name: Tag name
                 - value: Numeric value
                 - tag: WebId