v0.270.0: no update for a current app (R-679); an interrupted install is reported (R-681); a restore brings back the pinned version's health check (R-669); R-674

Five red-proofs. MinAgent 0.131.0 unchanged.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/web/templates/stacks.html

@@ -83,7 +83,7 @@
             {{else if not .Deployed}}
                 {{/* The endpoint refuses a non-installable template server-side; hiding the button
                      here keeps the two consistent rather than offering an action that will fail. */}}
-                {{if canInstall .Meta}}<a href="/stacks/{{.Name}}/deploy" class="btn btn-primary" onclick="return checkBeforeDeploy(event, '{{.Name}}')">{{T "stacks.telepites"}}</a>{{end}}
+                {{if .InstallInterrupted}}<div class="alert alert-warning" data-install-interrupted="true">{{T "stacks.install_interrupted"}}</div>{{end}}{{if canInstall .Meta}}<a href="/stacks/{{.Name}}/deploy" class="btn btn-primary" onclick="return checkBeforeDeploy(event, '{{.Name}}')">{{T "stacks.telepites"}}</a>{{end}}
                 <a href="{{appPageURL .Meta.Slug}}" class="btn btn-outline">{{T "stacks.reszletek"}}</a>
             {{else}}
                 {{/* Slice 4 (v0.238.0): the UPDATING and HELD checks come BEFORE isOperational. That