refactor:Enhances key verification and management UI

Refactors bulk key verification for improved error handling and reporting.
The UI is updated to use checkboxes for key selection and batch actions.
Adds detailed verification results modal to display success and failure details.
Improves key filtering, selection and actions for both valid and invalid keys.
Fixes visual glitches with section collapsing/expanding animations.

app/templates/base.html

@@ -141,7 +141,7 @@
             background-color: rgba(0, 0, 0, 0.8);
             color: white;
             font-weight: 500; /* font-medium */
-            z-index: 50;
+            z-index: 1000; /* Increased z-index */
             opacity: 0;
             transition: opacity 0.3s ease-in-out, transform 0.3s ease-in-out;
         }