feat: give the Insights traffic views heatmap two rows by default (#51240)

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/31677551360

Upstream-Ref: Automattic/jetpack@488e463

Author: chihsuan

CHANGELOG.md

@@ -22,6 +22,7 @@ This is an alpha version! The changes listed here are not final.
 - Detail pages: match the dashboard's tightened widget Card padding.
 - Exclude source map files from the distributed package.
 - Highlights: Follow the section's all-time and yearly date selection instead of always showing the most recent year, and show every metric on a dashboard whose layout carries no metric selection.
+- Insights: give the Traffic views activity heatmap two rows by default, so each day shows its view count.
 - Metric tabs: Spread cards evenly across the chart, wrap them before their contents overlap, match the prototype's card fill, spacing and headline value size, and render a lone metric as a static headline.
 - Posting activity: Show more history, larger cells, and a count-first tooltip, and drop the Fewer/More posts legend.
 - Post traffic activity: show more weeks per page in the views heatmap.

src/dashboard-layout.php

@@ -362,15 +362,15 @@ function get_dashboard_default_section_layouts() {
 				1,
 				1
 			),
-			// Row 5: daily views heatmap. One row tall, as in the prototype: at this
-			// height it renders compact squares, so the tile's width buys years of
-			// history instead of the ~14 weeks labelled cells would fit.
+			// Row 5: daily views heatmap. Two rows tall, as in the prototype: the
+			// cells are sized from the tile's height, and only at this height do they
+			// grow wide enough to label each day with its view count.
 			get_dashboard_default_widget_instance(
 				'default-traffic-views-activity-widget-instance',
 				'jpa/traffic-views-activity',
 				8,
 				4,
-				1
+				2
 			),
 			// Row 6: the comment leaderboards, shares, and tags.
 			get_dashboard_default_widget_instance(