controller v0.272.0: the backup page says when a whole-box backup does not fit (R-685); R-671, R-670, R-677

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

controller/internal/stacks/updateorder.go

@@ -210,3 +210,35 @@ func parseImageTag(tag string) (util.Version, string, bool) {
 	}
 	return v, suffix, true
 }
+
+// BehindSinceAge is the "Frissítés elérhető — N napja" age, in calendar days (R-677, v0.272.0). For a
+// DIGEST-ONLY move — every installed ref equals the catalog's and only a newer TESTED digest makes the app
+// behind (a floating tag re-tested) — the age counts from when that digest was tested (the ladder entry's
+// tested_at), not from the template's `catalog_since`, which dates the TAG and read „1 napja" for a digest
+// tested minutes earlier (seen 2026-09-24). Every other case keeps CatalogSinceAge. Both badge producers
+// call this, so they cannot disagree. Pinned by TestR677_DigestOnlyAgeFromTestedAt.
+func BehindSinceAge(s Stack, now time.Time) (int, bool) {
+	if digestOnlyBehind(s) && !s.CatalogTestedAt.IsZero() {
+		t := s.CatalogTestedAt.UTC()
+		today := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.UTC)
+		day := time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, time.UTC)
+		if d := int(today.Sub(day).Hours() / 24); d >= 0 {
+			return d, true
+		}
+		return 0, false
+	}
+	return s.Meta.CatalogSinceAge(now)
+}
+
+// digestOnlyBehind: every catalog service's ref equals the installed ref, and a newer tested digest exists.
+func digestOnlyBehind(s Stack) bool {
+	if s.AppConfig == nil || len(s.CatalogImages) == 0 || len(s.AppConfig.InstalledImages) != len(s.CatalogImages) {
+		return false
+	}
+	for svc, want := range s.CatalogImages {
+		if got, ok := s.AppConfig.InstalledImages[svc]; !ok || got.Ref != want {
+			return false
+		}
+	}
+	return digestBehind(s)
+}