refactor(django_nepkit/static/django_nepkit/js): debounce MutationObserver to avoid full scan and only init relevant forms and inputs

Added debounce and selective detection to limit re‑initialisation to mutations that affect observed elements, improving performance on pages with frequent DOM changes.

django_nepkit/static/django_nepkit/js/nepali-time-init.js

@@ -72,10 +72,35 @@
         initAll();
     }
 
+    // Re-initialise on DOM mutations so dynamically-injected forms
+    // (admin inlines, htmx swaps, etc.) get the same treatment.
+    // Debounced to avoid an O(document) scan on every keystroke, and
+    // filtered to only scan when a form/select ancestor was added.
     if (typeof MutationObserver !== 'undefined' && document.body) {
-        new MutationObserver(function () { initAll(); }).observe(document.body, {
-            childList: true,
-            subtree: true,
-        });
+        var debounceTimer = null;
+        new MutationObserver(function (mutations) {
+            var needsInit = false;
+            for (var i = 0; i < mutations.length; i++) {
+                var added = mutations[i].addedNodes;
+                for (var j = 0; j < added.length; j++) {
+                    var node = added[j];
+                    if (node.nodeType !== 1) continue;
+                    if (
+                        node.matches && (
+                            node.matches('form') ||
+                            node.matches('.nepkit-time-input') ||
+                            (node.querySelector && node.querySelector('.nepkit-time-input'))
+                        )
+                    ) {
+                        needsInit = true;
+                        break;
+                    }
+                }
+                if (needsInit) break;
+            }
+            if (!needsInit) return;
+            if (debounceTimer) clearTimeout(debounceTimer);
+            debounceTimer = setTimeout(function () { initAll(); }, 50);
+        }).observe(document.body, { childList: true, subtree: true });
     }
 })();