Svelte 5 does not support <style> or conditional {#if} blocks wrapping
<style> tags inside <svelte:head>. The parser treats them as raw-text
elements and reports '<script> was left open' at EOF.
Fix:
- Print media CSS moved to static/ae-print-badge.css (plain static file,
no framework magic needed — all selectors target global elements).
- svelte:head now uses a simple <link> to that file.
- $effect injects the @page size dynamically per template layout field,
avoiding the Svelte 5 parser limitation for conditional style injection.
- Badge_template interface in db_events.ts: added cfg_json / data_json
(standard Aether object fields that were missing from the type).