feat: add element_access_denied.svelte; use in badge review page

- New reusable element_access_denied.svelte with title, message, action props
- Badge review page: swap inline 'Access Denied' card with the component
- Project doc: all 6 steps complete, status → Complete

src/routes/events/[event_id]/(badges)/badges/[badge_id]/review/+page.svelte

@@ -30,6 +30,7 @@
     import { ArrowLeft, Check, Link, LoaderCircle, Mail, Printer } from 'lucide-svelte';
 
     import Comp_badge_review_form from '../ae_comp__badge_review_form.svelte';
+    import Element_access_denied from '$lib/elements/element_access_denied.svelte';
 
     let event_badge_id = $derived(page.params.badge_id);
     let event_id = $derived(page.params.event_id);
@@ -315,19 +316,11 @@
 
     {:else if passcode_checked && !passcode_valid}
         <!-- Invalid passcode -->
-        <div class="card p-6 space-y-4 max-w-sm">
-            <div class="flex items-center gap-2 text-error-500">
-                <h3 class="text-lg font-semibold">Access Denied</h3>
-            </div>
-            <p class="text-sm text-gray-700">{passcode_error}</p>
-            <button
-                type="button"
-                class="btn preset-tonal-surface w-full"
-                onclick={() => { passcode_checked = false; passcode_error = ''; entered_passcode = ''; }}
-            >
-                Try Again
-            </button>
-        </div>
+        <Element_access_denied
+            message={passcode_error}
+            action_label="Try Again"
+            on_action={() => { passcode_checked = false; passcode_error = ''; entered_passcode = ''; }}
+        />
     {/if}
 
 {:else if is_loading_idb || !event_badge_id}