Fix infinite hydration loop and stabilize global store synchronization

- Refactored layouts to derive account data from stable props instead of reactive stores.
- Wrapped store updates in untrack() with deep equality guards to prevent infinite re-renders.
- Resolved duplicate untrack declarations and missing imports across the project.
- Added fetch safeguards to Element_data_store to prevent redundant API calls.
- Standardized hydration patterns to break circular dependencies during initial load.

src/routes/events/[event_id]/+layout.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+    import { untrack } from 'svelte';
     interface Props {
         /** @type {import('./$types').LayoutData} */
         data: any;
@@ -27,7 +28,9 @@
 
     // Quickly save the data passed from the parent(s) to the Svelte stores, localStorage, and other.
     // $slct.account_id = data.account_id;
-    let ae_acct = $derived(data[$slct.account_id]);
+    // NOTE: Derived from data.account_id (prop) instead of $slct.account_id (store)
+    // to prevent circular dependency loops during hydration.
+    let ae_acct = $derived(data[data.account_id]);
 
     $effect(() => {
         if (log_lvl) {
@@ -43,8 +46,14 @@
 
     $effect(() => {
         if (ae_acct) {
-            $events_slct.event_session_obj_li = ae_acct.slct.event_session_obj_li;
-            $events_slct.event_location_obj_li = ae_acct.slct.event_location_obj_li;
+            untrack(() => {
+                if (JSON.stringify($events_slct.event_session_obj_li) !== JSON.stringify(ae_acct.slct.event_session_obj_li)) {
+                    $events_slct.event_session_obj_li = ae_acct.slct.event_session_obj_li;
+                }
+                if (JSON.stringify($events_slct.event_location_obj_li) !== JSON.stringify(ae_acct.slct.event_location_obj_li)) {
+                    $events_slct.event_location_obj_li = ae_acct.slct.event_location_obj_li;
+                }
+            });
         }
     });
 </script>