Fix price chart growing unbounded on item results page

Wrap the canvas in a fixed-height container so Chart.js's
responsive + maintainAspectRatio:false combo has a stable parent
to size against, instead of feeding back into itself each tick.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

templates/results.templ

@@ -128,7 +128,9 @@ templ itemResultsBody(d ItemResultsData) {
 				// Chart data rides on a data- attribute, not <script> content:
 				// templ interpolates (and escapes) attribute values but treats
 				// <script> bodies as raw text, leaving { expr } literal.
-				<canvas id="price-chart" height="120" data-chart={ d.HistoryChartJSON }></canvas>
+				<div class="relative h-64 w-full">
+					<canvas id="price-chart" data-chart={ d.HistoryChartJSON }></canvas>
+				</div>
 				<script src="/static/vendor/chart.umd.min.js"></script>
 				<script src="/static/js/price-chart.js"></script>
 			}