feat(badges): add 4×6 fanfold layout CSS for Epson single-sided stock

Introduces badge_layout_epson_4x6_fanfold.css (layout code badge_4x6_fanfold)
for the Axonius Adapt 2026 June show. Wires @page size to 4in×6in in the print
page and cleans up the stale 4in×12in default. Imports new CSS in badge component.
Measured stock: 4in × 6in portrait with 5/8in lanyard hole 1/4in from top.

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

src/routes/events/[event_id]/(badges)/badges/[badge_id]/ae_comp__badge_obj_view.svelte

@@ -72,6 +72,7 @@ let {
 // Each file scopes rules under [data-layout="..."] on the wrapper section.
 // @page rules (paper size) are injected per-template in print/+page.svelte.
 import '$lib/ae_events/badges/css/badge_layout_epson_4x5_fanfold.css';
+import '$lib/ae_events/badges/css/badge_layout_epson_4x6_fanfold.css';
 import '$lib/ae_events/badges/css/badge_layout_zebra_zc10l_pvc.css';
 
 import { untrack } from 'svelte';

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

@@ -293,8 +293,10 @@ let page_size_css = $derived(
     $lq__event_badge_template_obj?.layout === 'badge_3.5x5.5_pvc'
         ? '3.5in 5.5in'
         : $lq__event_badge_template_obj?.layout === 'badge_4x5_fanfold'
-          ? '4in 10in'
-          : '4in 12in' // Default: badge_4x6_fanfold or layout not yet set
+          ? '4in 10in' // duplex fanfold: 5in front + 5in back = 10in strip
+          : $lq__event_badge_template_obj?.layout === 'badge_4x6_fanfold'
+            ? '4in 6in' // single-sided fanfold: front only
+            : '4in 6in' // fallback: unknown layout, assume single-sided 4×6
 );
 // @page size + optional per-template margin override from cfg_json.print_margin.
 // print_margin_cfg is parsed from the template's cfg_json field — allows per-event