v0.4.7: Protected stack detail pages + backup page caching

Task 1: Protected stacks with .felhom.yml (slug) are now clickable
on both dashboard and stacks pages. "Részletek" button added to
protected stack actions section. Filebrowser .felhom.yml updated
with resources metadata.

Task 2: Backup page now reads from a cached FullBackupStatus that
refreshes every 5 minutes in background + after each backup run.
Page loads instantly instead of blocking on restic/docker subprocesses.

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

controller/internal/web/templates/dashboard.html

@@ -124,7 +124,7 @@
 
 <div class="stack-list">
     {{range .Stacks}}
-    <div class="stack-card stack-state-{{stateColor .State}}"{{if not .Protected}} data-href="/apps/{{.Meta.Slug}}"{{end}}>
+    <div class="stack-card stack-state-{{stateColor .State}}"{{if .Meta.Slug}} data-href="/apps/{{.Meta.Slug}}"{{end}}>
         <div class="stack-info">
             <img class="stack-logo" src="{{logoURL .Meta.Slug}}"
                  alt="{{.Meta.DisplayName}}" onerror="this.onerror=function(){this.style.display='none'};this.src='{{logoPNGURL .Meta.Slug}}'">