fix(launcher): fix cfg modal default-open and outside-click persistence

Two bugs in the Launcher Config Modal after the Drawer→Modal migration:
1. Pre-existing persisted configs (missing hide_drawer__cfg field) caused
   !undefined = true, opening the modal on every fresh load. Fixed by adding
   a field-level initialization guard after the full-object guard.
2. $-syntax writes inside untrack() were suppressed by svelte-persisted-store,
   so outside-click closure was never persisted. Fixed by using events_loc.update()
   directly to ensure the write reaches localStorage serialization. Added equality
   guard to effect 1 to prevent spurious modal flicker from whole-store re-fires.

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

src/routes/events/[event_id]/(launcher)/launcher/+layout.svelte

@@ -91,6 +91,36 @@ if (!$events_loc?.launcher) {
         hide_drawer__debug: true
     };
 }
+// WHY: The initialization block above only runs when launcher is completely absent.
+// If the user has an older persisted config (from before the Modal migration),
+// hide_drawer__cfg may be missing → undefined → !undefined = true → modal opens
+// on every load. Explicitly initialize it here to ensure it is always a boolean.
+if ($events_loc.launcher.hide_drawer__cfg === undefined) {
+    $events_loc.launcher.hide_drawer__cfg = true;
+}
+
+let modal_cfg_open = $state(!$events_loc.launcher.hide_drawer__cfg);
+
+// Sync store → modal: biohazard button writes hide_drawer__cfg = false to open.
+// Equality guard prevents spurious writes from unrelated $events_loc updates
+// (Svelte 4 whole-store subscription fires on every field write to the store).
+$effect(() => {
+    const should_open = !$events_loc.launcher.hide_drawer__cfg;
+    if (modal_cfg_open !== should_open) {
+        modal_cfg_open = should_open;
+    }
+});
+
+// Sync modal → store: use events_loc.update() directly rather than $-syntax so
+// the write always reaches the persisted store's serialization. $-syntax writes
+// inside $effect contexts may be suppressed and not trigger localStorage persistence.
+$effect(() => {
+    const should_hide = !modal_cfg_open;
+    events_loc.update((loc) => {
+        if (loc.launcher) loc.launcher.hide_drawer__cfg = should_hide;
+        return loc;
+    });
+});
 
 // Generate a stable per-device client ID on first load and persist it.
 // events_loc is backed by svelte-persisted-store (localStorage) so this
@@ -898,59 +928,41 @@ $effect(() => {
     </button>
 </div>
 
-<Drawer
+<Modal
-    dismissable={false}
+    bind:open={modal_cfg_open}
-    onclick={() => ($events_loc.launcher.hide_drawer__cfg = true)}
+    autoclose={false}
-    class="w-full border border-gray-300 bg-orange-50 opacity-90 transition-all duration-300 hover:opacity-97 md:w-96 lg:w-[32rem] dark:border-gray-600 dark:bg-slate-800"
+    outsideclose
-    placement="left"
+    size="xl"
-    {...{
+    class="relative flex flex-col items-center justify-center p-0 overflow-hidden"
-        transitionType: 'fly',
+    id="modal_cfg">
-        transitionParams: {
+    <Launcher_cfg></Launcher_cfg>
-            x: -520,
-            duration: 200,
-            easing: sineIn
-        }
-    }}
-    bind:hidden={$events_loc.launcher.hide_drawer__cfg}
-    id="sidebar1">
-    <!-- Stop-propagation wrapper: prevents clicks inside the visual panel from
-         bubbling up to the <dialog> element. The onclick on the <Drawer> above
-         is spread through to the native <dialog> by Flowbite, overriding its
-         broken outsideclose detection. With this wrapper, ONLY genuine backdrop
-         clicks (outside the visible panel) reach the dialog and close the drawer. -->
-    <!-- svelte-ignore a11y_click_events_have_key_events a11y_no_static_element_interactions -->
-    <div role="presentation" onclick={(e) => e.stopPropagation()}>
-        <Launcher_cfg></Launcher_cfg>
 
-        <hr class="my-2 border-gray-300 dark:border-gray-600" />
+    <div
-
+        class="bg-surface-100-900 flex max-w-full flex-row flex-wrap items-center justify-center gap-2 border-t border-surface-500/10 p-4">
-        <div
+        <a
-            class="flex max-w-md flex-row flex-wrap items-center justify-center gap-0.5">
+            href="/events/{$events_slct.event_id}"
+            class="btn btn-sm preset-tonal-primary hover:preset-filled-primary-500">
+            <Search size="1em" class="m-1" />
+            Session Search
+        </a>
+        {#if $events_slct?.event_location_id}
             <a
-                href="/events/{$events_slct.event_id}"
+                href="/events/{$events_slct.event_id}/location/{$events_slct.event_location_id}"
                 class="btn btn-sm preset-tonal-primary hover:preset-filled-primary-500">
-                <Search size="1em" class="m-1" />
+                <MapPin size="1em" class="m-1" />
-                Session Search
+                View Selected Location
             </a>
-            {#if $events_slct?.event_location_id}
+        {/if}
-                <a
+        {#if $events_slct?.event_session_id}
-                    href="/events/{$events_slct.event_id}/location/{$events_slct.event_location_id}"
+            <a
-                    class="btn btn-sm preset-tonal-primary hover:preset-filled-primary-500">
+                href="/events/{$events_slct.event_id}/session/{$events_slct.event_session_id}"
-                    <MapPin size="1em" class="m-1" />
+                class="btn btn-sm preset-tonal-primary hover:preset-filled-primary-500">
-                    View Selected Location
+                <GraduationCap size="1em" class="m-1" />
-                </a>
+                View Selected Session
-            {/if}
+            </a>
-            {#if $events_slct?.event_session_id}
+        {/if}
-                <a
-                    href="/events/{$events_slct.event_id}/session/{$events_slct.event_session_id}"
-                    class="btn btn-sm preset-tonal-primary hover:preset-filled-primary-500">
-                    <GraduationCap size="1em" class="m-1" />
-                    View Selected Session
-                </a>
-            {/if}
-        </div>
     </div>
-</Drawer>
+</Modal>
 
 <Drawer
     activateClickOutside={false}