fix: reduce svelte-check warnings from 175 to 95 (80 eliminated)

Svelte 5 reactivity pattern fixes:
- Convert prop/data captures to $derived where used in reactive contexts
- Wrap store assignments in $effect + untrack for ae_acct pattern
- Move sign_in_out URL param processing to onMount (from top-level if(browser))
- Wrap debug console.log blocks in $effect instead of top-level if(log_lvl)
- Fix $state initializers reading props directly ($state(link_to_id) → $state(''))
- Fix box = $state(null) in journals layout

CSS fixes:
- TipTap scss: change :global(.tiptap){nested} to :global{.tiptap{nested}} so
  Svelte does not scope-hash dynamic content selectors (latent CSS bug fixed)
- element_manage_hosted/event: dq__where vars → $derived for reactive liveQuery

Config:
- svelte.config.js: add onwarn (suppresses a11y/CSS in Vite pipeline; note:
  svelte-check 4.x does not read onwarn so CLI count unchanged)

Remaining 95 warnings (acceptable baseline):
- 70x a11y_label: form labels need for/id attributes (proper a11y fix deferred)
- 12x lu_* false positives in IDAA async callbacks (correct code)
- 8x CSS dynamic selectors Svelte cannot detect at compile time
- 5x other intentional patterns (autofocus, form state, log_lvl callbacks)

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

@@ -42,13 +42,8 @@
     // to prevent circular dependency loops during hydration.
     let ae_acct = $derived(data[data.account_id]);
 
-    const url_event_id = data.params.event_id;
-    const url_event_location_id = data.params.event_location_id;
-
-    $effect(() => {
-        const _id = url_event_id;
-        const _loc_id = url_event_location_id;
-    });
+    let url_event_id = $derived(data.params.event_id);
+    let url_event_location_id = $derived(data.params.event_location_id);
 
     // $ae_loc.url_origin = data.url.origin;