B2b: decommission orchestration + missing-storage indicator + re-enroll fix (v0.65.0)

agentapi.Decommission + handleStorageDecommission (migrate-all-or-none, Change 2):
migrate-then-decommission via the migration done-hook, or decommission-anyway (stop
apps, keep HDD_PATH). 'Hiányzó tárhely' badge on dashboard/stacks/app card when an
app's drive is decommissioned/disconnected/absent. Change 4: registerStoragePath
clears the decommissioned marker on re-enroll (ClearDecommissioned had no callers).
Non-hollow tests incl. mutation-proven Change-4 companion.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

controller/internal/web/templates/stacks.html

@@ -38,6 +38,7 @@
             </div>
             <span class="stack-state-badge state-{{stateColor .State}}">{{stateLabel .State}}</span>
             {{if .Orphaned}}<span class="badge badge-orphaned">Elavult</span>{{end}}
+            {{$ms := index $.MissingStorage .Name}}{{if $ms}}<span class="badge badge-missing-storage" title="Az alkalmazás adattárolója nem elérhető. Csatlakoztasd újra a meghajtót, vagy helyezd át az adatokat.">⚠ Hiányzó tárhely: {{$ms}}</span>{{end}}
         </div>
 
         {{if .Meta.Description}}