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]/(pres_mgmt)/presenter/[presenter_id]/+page.svelte

@@ -46,7 +46,7 @@
     // Variables
     // Quickly save the data passed from the parent(s) to the Svelte stores, localStorage, and other.
     // $slct.account_id = data.account_id;
-    let ae_acct = data[$slct.account_id];
+    let ae_acct = data[data.account_id];
     if (log_lvl) {
         console.log(`ae_acct = `, ae_acct);
     }