ui: drop the Decoded FCI caption in the file manager info block

The decoded FCI items now follow the FID/type/size line directly; the
snapshot detail view keeps its caption. Test updated to assert the
caption is absent; SW cache v120 -> v121.

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'otaman-v120';
+const CACHE = 'otaman-v121';
 const URLS = [
   'index.html',
   'help.html',