style: fix missed Phase 1/2 items — FA→Lucide, a11y, variant-* cleanup

- +layout.svelte: replace fa-cog/fa-spinner spinners with LoaderCircle;
  variant-filled-primary → preset-filled-primary on reload button
- events/+page.svelte: fa-calendar-alt → CalendarDays, fa-exclamation-triangle
  → TriangleAlert (+ text-red-500 → text-error-500), fa-spinner → LoaderCircle
- sign_in_out.svelte: fa-times → X, fa-sign-in-alt → LogIn
- journals/+layout.svelte: fa-arrow-right → ArrowRight
- journal_entry_header.svelte: fix focus:ring-0 → focus:ring-2 focus:ring-primary-500
  (WCAG 2.1 AA — removes keyboard focus indicator violation)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/events/[event_id]/sign_in_out.svelte

@@ -33,6 +33,7 @@
         events_trigger,
         events_trig_kv
     } from '$lib/stores/ae_events_stores';
+    import { X, LogIn } from 'lucide-svelte';
 
     onMount(() => {
         console.log('Browser environment detected.');
@@ -209,7 +210,7 @@
                 alert('You have been signed out.');
             }}
         >
-            <span class="fas fa-times mx-1"></span>
+            <X size="1em" class="inline mx-1" />
             Sign Out
             {$lq__auth__event_presenter_obj?.given_name
                 ? `- ${$lq__auth__event_presenter_obj?.given_name}`
@@ -269,7 +270,7 @@
                         // $events_slct.event_presenter_id = $events_sess.auth__person.presenter_id;
                     }}
                 >
-                    <span class="fas fa-sign-in-alt mx-1"></span>
+                    <LogIn size="1em" class="inline mx-1" />
                     Sign In
                 </button>
             </div>