style(backup): use nebula translucent buttons; left-align location actions

Two follow-ups to the button restyle:

- On the nebula theme, primary/danger CTAs are translucent (rgba accent/danger
  fill + white text + border), not the solid generic .btn-primary. The earlier
  change only added the backup classes to the generic groups, so on nebula the
  Add location / Save changes / Delete buttons fell back to a solid fill with
  dark text. Add .backup-primary-btn and .backup-danger-btn to the
  [data-theme="nebula"] groups too, so they match the config-page buttons.

- The per-location action row used justify-content: space-between, throwing the
  two buttons to opposite edges. Switch to flex-start with a gap (like
  .config-actions) and put Save changes (primary) before Delete location.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>

containers/libreportal/frontend/css/backup.css

@@ -454,9 +454,9 @@
 
 .backup-location-actions {
     display: flex;
-    justify-content: space-between;
+    justify-content: flex-start;
     align-items: center;
-    gap: 10px;
+    gap: 12px;
     margin-top: 16px;
     padding-top: 14px;
     border-top: 1px solid rgba(var(--text-rgb), 0.06);

containers/libreportal/frontend/css/themes.css

@@ -266,7 +266,8 @@
 
 [data-theme="nebula"] .uninstall-btn,
 [data-theme="nebula"] .btn-uninstall,
-[data-theme="nebula"] .btn-danger {
+[data-theme="nebula"] .btn-danger,
+[data-theme="nebula"] .backup-danger-btn {
   background: rgba(var(--status-danger-rgb), 0.35) !important;
   color: var(--text-primary) !important;
   border: 1px solid rgba(var(--status-danger-rgb), 0.65) !important;
@@ -277,7 +278,8 @@
 
 [data-theme="nebula"] .uninstall-btn:hover:not(:disabled),
 [data-theme="nebula"] .btn-uninstall:hover:not(:disabled),
-[data-theme="nebula"] .btn-danger:hover:not(:disabled) {
+[data-theme="nebula"] .btn-danger:hover:not(:disabled),
+[data-theme="nebula"] .backup-danger-btn:hover:not(:disabled) {
   background: rgba(var(--status-danger-rgb), 0.50) !important;
   border-color: rgba(var(--status-danger-rgb), 0.85) !important;
   transform: translateY(-1px);
@@ -286,6 +288,7 @@
 [data-theme="nebula"] .manage-btn,
 [data-theme="nebula"] .btn-manage,
 [data-theme="nebula"] .btn-primary,
+[data-theme="nebula"] .backup-primary-btn,
 [data-theme="nebula"] .app-card .manage-btn,
 [data-theme="nebula"] .app-card-actions .manage-btn {
   background: rgba(var(--accent-rgb), 0.35) !important;
@@ -299,6 +302,7 @@
 [data-theme="nebula"] .manage-btn:hover:not(:disabled),
 [data-theme="nebula"] .btn-manage:hover:not(:disabled),
 [data-theme="nebula"] .btn-primary:hover:not(:disabled),
+[data-theme="nebula"] .backup-primary-btn:hover:not(:disabled),
 [data-theme="nebula"] .app-card .manage-btn:hover:not(:disabled),
 [data-theme="nebula"] .app-card-actions .manage-btn:hover:not(:disabled) {
   background: rgba(var(--accent-rgb), 0.50) !important;

containers/libreportal/frontend/js/components/backup/backup-page.js

@@ -672,8 +672,8 @@ class BackupPage {
                 </div>
             </div>
             <div class="backup-location-actions">
-                <button class="backup-danger-btn" data-action="delete-location" data-loc="${idx}">Delete location</button>
                 <button class="backup-primary-btn" data-action="save-location" data-loc="${idx}">Save changes</button>
+                <button class="backup-danger-btn" data-action="delete-location" data-loc="${idx}">Delete location</button>
             </div>
         `;
     }