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/modern.html

@@ -79,6 +79,14 @@ OF THIS SOFTWARE.
                     <div class="chart-title">By Category</div>
                     <canvas id="categories-chart"></canvas>
                 </div>
+                <div class="chart-container">
+                    <div class="chart-title">By Runner</div>
+                    <canvas id="runners-chart"></canvas>
+                </div>
+                <div class="chart-container">
+                    <div class="chart-title">By Source</div>
+                    <canvas id="sources-chart"></canvas>
+                </div>
             </div>
         </div>
     </div>