feat(admin): add dashboard overview charts and log pagination

Enhance the admin panel by introducing visual overview charts for upload and storage trends, along with status bars for system metrics.

Additionally, implement pagination for the admin logs view, allowing users to navigate through log entries with configurable page sizes. Corresponding CSS styles have been added for the new charts, metrics grid, and pagination controls.

backend/templates/pages/admin_logs.html

@@ -54,6 +54,7 @@
           <option value="asc" {{if eq .Data.Logs.Sort "asc"}}selected{{end}}>Oldest first</option>
         </select>
       </label>
+      <input type="hidden" name="per" value="{{.Data.Logs.PerPage}}">
       <button class="button button-primary" type="submit">Filter</button>
     </form>
 
@@ -62,7 +63,7 @@
         <div class="table-header">
           <div>
             <h2>Log entries</h2>
-            <p>Showing up to 500 entries. {{.Data.Logs.TotalShown}} currently visible.</p>
+            <p>{{.Data.Logs.Total}} entries match these filters.</p>
           </div>
         </div>
         <div class="admin-table-wrap">
@@ -98,6 +99,21 @@
             </tbody>
           </table>
         </div>
+
+        <div class="pagination-bar">
+          <nav class="pagination" aria-label="Pagination">
+            {{if .Data.Logs.HasPrev}}<a class="button button-outline button-sm" href="{{.Data.Logs.PrevHref}}">← Prev</a>{{else}}<span class="button button-outline button-sm is-disabled" aria-disabled="true">← Prev</span>{{end}}
+            {{range .Data.Logs.PageLinks}}<a class="button button-sm {{if .Active}}is-active{{else}}button-outline{{end}}" href="{{.Href}}">{{.Page}}</a>{{end}}
+            {{if .Data.Logs.HasNext}}<a class="button button-outline button-sm" href="{{.Data.Logs.NextHref}}">Next →</a>{{else}}<span class="button button-outline button-sm is-disabled" aria-disabled="true">Next →</span>{{end}}
+          </nav>
+          <label class="per-page-control">
+            <span>Per page</span>
+            <select data-per-page="logs" aria-label="Items per page">
+              {{range .Data.Logs.PerPageOptions}}<option value="{{.}}" {{if eq . $.Data.Logs.PerPage}}selected{{end}}>{{.}}</option>{{end}}
+            </select>
+          </label>
+        </div>
+        <p class="pagination-summary">Showing {{.Data.Logs.RangeFrom}}–{{.Data.Logs.RangeTo}} of {{.Data.Logs.Total}} · Page {{.Data.Logs.Page}} of {{.Data.Logs.TotalPages}}</p>
       </div>
     </div>
   </div>