Pass temporal fields through A2A to frontend

- Update research_gateway.py to extract temporal fields from partial_metrics
- Update researcher.py progress_callback to pass temporal data to add_metric
- Enables fiscal period display (FY 2023, Q3 2024) in Key Data panel

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/nodes/research_gateway.py

@@ -146,9 +146,13 @@ async def wait_for_completion(
                 value = metric.get("value")
                 if not source or not metric_name:
                     continue
+                # Extract temporal fields
+                end_date = metric.get("end_date")
+                fiscal_year = metric.get("fiscal_year")
+                form = metric.get("form")
                 metric_key = f"{source}:{metric_name}:{value}"
                 if metric_key not in emitted_metrics:
-                    progress_callback(source, metric_name, value)
+                    progress_callback(source, metric_name, value, end_date, fiscal_year, form)
                     emitted_metrics.add(metric_key)
 
         if status == "completed":

src/nodes/researcher.py

@@ -76,11 +76,13 @@ def researcher_node(state, workflow_id=None, progress_store=None):
             add_activity_log(workflow_id, step, message)
 
     # Create progress callback for granular metric events
-    def progress_callback(source: str, metric: str, value):
+    def progress_callback(source: str, metric: str, value,
+                          end_date: str = None, fiscal_year: int = None, form: str = None):
         if workflow_id and progress_store:
             # Import here to avoid circular imports
             from src.services.workflow_store import add_metric
-            add_metric(workflow_id, source, metric, value)
+            add_metric(workflow_id, source, metric, value,
+                       end_date=end_date, fiscal_year=fiscal_year, form=form)
 
     try:
         # Fetch via Research Gateway (A2A protocol)