fix(mobile): stop the task drawer's priority/due row overflowing

On a phone the detail drawer's field grid stayed two columns, so each
field got half the viewport. Prioritet collapsed to "Ing" and the due
row — a date input plus fixed-width time and duration fields — ran off
the right edge. Below 560px the grid now stacks to one column per field
and the due row wraps.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/lib/components/TaskDetail.svelte

@@ -1115,5 +1115,21 @@
 			width: auto;
 			border-left: 0;
 		}
+
+		/* Two columns is half a phone each: Prioritet collapses to "Ing" and the
+		   due-row (date + fixed-width time + duration) runs off the right edge. One
+		   column per field gives each its full width; the due-row wraps if even that
+		   is not enough. */
+		.grid {
+			grid-template-columns: 1fr;
+		}
+
+		.due {
+			flex-wrap: wrap;
+		}
+
+		.due input[type='date'] {
+			flex: 1 1 100%;
+		}
 	}
 </style>