fix: Add MCP 'executing' state for process flow visualization

- Add set_mcp_executing() to workflow_store.py
- Call it at start of research phase in researcher.py
- MCP containers now show 'executing' while fetching data

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

src/nodes/researcher.py

@@ -102,6 +102,11 @@ def researcher_node(state, workflow_id=None, progress_store=None):
                        end_date=end_date, fiscal_year=fiscal_year, form=form)
 
     try:
+        # Set all MCP servers to "executing" state before research starts
+        if workflow_id and progress_store:
+            from src.services.workflow_store import set_mcp_executing
+            set_mcp_executing(workflow_id)
+
         # Fetch via Research Gateway (A2A protocol)
         print("[Research Gateway] Calling Research Service via A2A...")
         result = asyncio.run(_fetch_via_research_gateway(

src/services/workflow_store.py

@@ -79,6 +79,13 @@ def add_metric(workflow_id: str, source: str, metric: str, value,
             WORKFLOWS[workflow_id]["mcp_status"][source] = "completed"
 
 
+def set_mcp_executing(workflow_id: str):
+    """Set all MCP servers to 'executing' state when research starts."""
+    if workflow_id in WORKFLOWS and "mcp_status" in WORKFLOWS[workflow_id]:
+        for source in WORKFLOWS[workflow_id]["mcp_status"]:
+            WORKFLOWS[workflow_id]["mcp_status"][source] = "executing"
+
+
 def _quarter_from_date(date_str: str) -> int:
     """Extract quarter number from a date string (YYYY-MM-DD)."""
     if not date_str: