[loop-cycle-1666] fix: replace remaining deprecated utcnow() in calm.py (#633) (#644)

src/dashboard/routes/calm.py

@@ -1,5 +1,5 @@
 import logging
-from datetime import date, datetime
+from datetime import UTC, date, datetime
 
 from fastapi import APIRouter, Depends, Form, HTTPException, Request
 from fastapi.responses import HTMLResponse
@@ -226,7 +226,7 @@ async def post_evening_ritual(
     )
     for task in active_tasks:
         task.state = TaskState.DEFERRED  # Or DONE, depending on desired archiving logic
-        task.deferred_at = datetime.utcnow()
+        task.deferred_at = datetime.now(UTC)
         db.add(task)
 
     db.commit()
@@ -279,7 +279,7 @@ async def start_task(
         raise HTTPException(status_code=404, detail="Task not found")
 
     task.state = TaskState.NOW
-    task.started_at = datetime.utcnow()
+    task.started_at = datetime.now(UTC)
     db.add(task)
     db.commit()
 
@@ -309,7 +309,7 @@ async def complete_task(
         raise HTTPException(status_code=404, detail="Task not found")
 
     task.state = TaskState.DONE
-    task.completed_at = datetime.utcnow()
+    task.completed_at = datetime.now(UTC)
     db.add(task)
     db.commit()
 
@@ -338,7 +338,7 @@ async def defer_task(
         raise HTTPException(status_code=404, detail="Task not found")
 
     task.state = TaskState.DEFERRED
-    task.deferred_at = datetime.utcnow()
+    task.deferred_at = datetime.now(UTC)
     db.add(task)
     db.commit()