fix: move IDAA recovery meeting page browser block into onMount

Two state_referenced_locally warnings on data prop in
recovery_meetings/[event_id]/+page.svelte: reading a $props()
rune synchronously in a top-level if (browser) block only captures
the initial value.

Move the postMessage block into onMount (browser-only by nature);
remove the now-redundant 'browser' import.

src/routes/idaa/(idaa)/recovery_meetings/[event_id]/+page.svelte

@@ -9,8 +9,7 @@
     let log_lvl: number = 0;
 
     // *** Import Svelte specific
-    import { onDestroy, untrack } from 'svelte';
-    import { browser } from '$app/environment';
+    import { onMount, onDestroy, untrack } from 'svelte';
 
     // *** Import other supporting libraries
     // import { Modal } from 'flowbite-svelte';
@@ -91,13 +90,11 @@
         })
     );
 
-    if (browser) {
-        console.log('Browser environment detected.');
-
-        // NOTE: Use data[data.account_id].slct.event_id (from the load function / URL params),
-        // NOT $idaa_slct.event_id (the store). The store is updated by a $effect that runs
-        // after this synchronous block — reading it here would send the old/null value and
-        // fail to update the parent page URL.
+    // NOTE: onMount runs in browser only, so no browser guard needed.
+    // Use data[data.account_id].slct.event_id (from the load function / URL params),
+    // NOT $idaa_slct.event_id (the store) — the store is set by a $effect and may not
+    // reflect the correct value yet at this point.
+    onMount(() => {
         let message = { event_id: data[data.account_id]?.slct?.event_id ?? null };
         window.parent.postMessage(message, '*');
 
@@ -107,7 +104,7 @@
             );
             window.parent.postMessage({ scroll_to: 0 }, '*'); // This should be in pixels
         }
-    }
+    });
 
     onDestroy(() => {
         if (log_lvl) {