Add draggable splitter between APDU list and detail view

- Insert .splitter div between .apdu-list and .apdu-detail
- Replace flex:1 / max-height:40% with --detail-height CSS var
- Drag handler with clamp 10%-80%, persisted in localStorage
- Bump 1.22.12, SW cache v43->v44

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'simtrace-analyser-v43';
+const CACHE = 'simtrace-analyser-v44';
 
 const PRECACHE = [
     'index.html',