fix(admin): improve overview bar chart layout and alignment

backend/libs/handlers/accounts_test.go

@@ -695,6 +695,35 @@ func TestAPIDocsHeaderReflectsLoggedOutUser(t *testing.T) {
 	}
 }
 
+func TestAdminOverviewChartsUseZeroAndFullHeights(t *testing.T) {
+	now := time.Now().UTC()
+	today := time.Date(now.Year(), now.Month(), now.Day(), 12, 0, 0, 0, time.UTC)
+	overview := buildAdminOverview([]services.AdminBox{{
+		ID:        "box1",
+		CreatedAt: today,
+		TotalSize: 1024,
+	}}, services.AdminStats{TotalBoxes: 1, TotalFiles: 1, TotalSize: 1024})
+
+	for i, bar := range overview.UploadDays {
+		want := 0
+		if i == len(overview.UploadDays)-1 {
+			want = 100
+		}
+		if bar.Height != want {
+			t.Fatalf("upload bar %d height = %d, want %d", i, bar.Height, want)
+		}
+	}
+	for i, bar := range overview.StorageDays {
+		want := 0
+		if i == len(overview.StorageDays)-1 {
+			want = 100
+		}
+		if bar.Height != want {
+			t.Fatalf("storage bar %d height = %d, want %d", i, bar.Height, want)
+		}
+	}
+}
+
 func TestAdminStorageProviderPagesOnlyRenderRelevantFields(t *testing.T) {
 	app, cleanup := newTestApp(t)
 	defer cleanup()