Add By Runner and By Source charts to playtime reports

- Add runners and sources charts to modern and platinum templates
- Update responsive layout to use grid for multiple charts
- Update .gitignore to exclude pga.db

templates/glassmorphism.css

@@ -274,14 +274,14 @@ body {
 
 /* Charts */
 .charts-wrapper {
-    display: flex;
-    gap: 24px;
+    display: grid;
+    grid-auto-columns: minmax(280px, 450px);
+    grid-template-columns: repeat(auto-fill, minmax(280px, 450px));
+    grid-gap: 24px;
     justify-content: center;
-    flex-wrap: wrap;
 }
 
 .chart-container {
-    flex: 1;
     min-width: 280px;
     max-width: 450px;
     padding: 16px;