feat: Add dashboard charts with interactivity and basic authentication support

web/templates/partials/charts.html

@@ -0,0 +1,37 @@
+<div
+  id="charts-panel"
+  class="panel"
+  style="margin-top: 16px"
+  x-data="{ expanded: true }"
+>
+  <div class="chart-head">
+    <div>
+      <div class="label">Opportunity Trend</div>
+      <div class="meta">Recent opportunities from DuckDB. Updated {{ generated_at }}</div>
+    </div>
+    <button type="button" class="button secondary" x-on:click="expanded = !expanded">
+      <span x-text="expanded ? 'Hide chart' : 'Show chart'"></span>
+    </button>
+  </div>
+
+  <div x-show="expanded" x-transition style="margin-top: 16px">
+    <div class="card" style="padding: 12px">
+      {% if has_chart_data %}
+      <canvas id="opportunity-chart" class="chart-canvas"></canvas>
+      <script>
+        window.arbitradeRenderCharts(
+          {{ {
+            "has_chart_data": has_chart_data,
+            "labels": labels,
+            "net_pct_values": net_pct_values,
+            "est_profit_values": est_profit_values,
+            "cycles": cycles,
+          } | tojson }}
+        );
+      </script>
+      {% else %}
+      <div class="meta">No opportunity data yet.</div>
+      {% endif %}
+    </div>
+  </div>
+</div>