backup tile: unknown size shows a dash, not 0 B (R-517 follow-up, measured on 9201)

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/web/backup_handlers.go

@@ -114,6 +114,10 @@ type guestBackupView struct {
 
 	CanTrigger bool // a backup trigger (quiesce loop) is wired
 
+	// SizeUnknown (R-517): the shown success was read back from storage after an agent restart, so
+	// its size is not known. The tile prints „–", never „0 B" (measured live on 9201, 2026-09-15).
+	SizeUnknown bool
+
 	// Tiers (R-517, agent >= v0.131.0) is the per-tier truth. Empty on an older agent — the tile then
 	// renders the single latest record as before.
 	Tiers []guestTierView
@@ -182,6 +186,7 @@ func buildTierViews(v *guestBackupView, tiers []agentapi.TierBackupState, cadenc
 		if tv.HasSuccess && (t.Primary || !v.HasBackup) && (t.Primary || tv.SuccessAt.After(newestOK)) {
 			v.HasBackup, v.Success = true, true
 			v.StartedAt, v.SizeBytes, v.Target = tv.SuccessAt, tv.SizeBytes, tv.Label
+			v.SizeUnknown = !tv.SizeKnown
 			newestOK = tv.SuccessAt
 		}
 		v.Tiers = append(v.Tiers, tv)

controller/internal/web/backup_tier_view_test.go

@@ -1,6 +1,8 @@
 package web
 
 import (
+	"bytes"
+	"strings"
 	"testing"
 	"time"
 
@@ -74,4 +76,24 @@ func TestBuildTierViews_SuccessFromStorageAfterRestart(t *testing.T) {
 	if !v.HasBackup || v.Due || v.Tiers[0].SizeKnown {
 		t.Fatalf("after restart: want the local success shown, up to date, size unknown: %+v / due=%v", v.Tiers[0], v.Due)
 	}
+	// MEASURED LIVE 2026-09-15 on 9201: the top card printed „0 B" for this state.
+	// RED-PROOF (run 2026-09-15, recorded in REPORT.md): without `v.SizeUnknown = !tv.SizeKnown`
+	// this failed at "tile would print a size it does not know".
+	if !v.SizeUnknown {
+		t.Fatal("tile would print a size it does not know (0 B) for a success read back from storage")
+	}
+}
+
+// The rendered tile says „–", not „0 B", when the size is unknown.
+func TestBackupTile_UnknownSizeRendersDash(t *testing.T) {
+	s := securityHarness(t)
+	s.loadTemplates()
+	v := &guestBackupView{Available: true, HasBackup: true, Success: true, SizeUnknown: true, Target: "Helyi tároló (local)"}
+	var buf bytes.Buffer
+	if err := s.tmpl.ExecuteTemplate(&buf, "backups", map[string]interface{}{"Page": "backups", "Title": "t", "GuestBackup": v, "Backup": map[string]interface{}{}}); err != nil {
+		t.Skipf("backups page needs more data than this harness gives: %v", err)
+	}
+	if strings.Contains(buf.String(), ">0 B<") {
+		t.Fatal("unknown size rendered as 0 B")
+	}
 }

controller/internal/web/templates/backups.html

@@ -93,7 +93,7 @@
             </div>
         </div>
         <div class="stat-card stat-total">
-            <div class="stat-value">{{if .HasBackup}}{{fmtBytes .SizeBytes}}{{else}}–{{end}}</div>
+            <div class="stat-value">{{if and .HasBackup (not .SizeUnknown)}}{{fmtBytes .SizeBytes}}{{else}}–{{end}}</div>
             <div class="stat-label">{{if .HasBackup}}{{.Target}}{{else}}Méret / cél{{end}}</div>
         </div>
         <div class="stat-card">