fix: keep empty-state header visible

Author: Astro-Han

internal/ui/model.go

@@ -329,7 +329,11 @@ func (m Model) View() string {
 	}
 	padding := ""
 	if contentLines < diffHeight {
-		padding = strings.Repeat("\n", diffHeight-contentLines)
+		paddingLines := diffHeight - contentLines
+		if contentLines == 0 && paddingLines > 0 {
+			paddingLines--
+		}
+		padding = strings.Repeat("\n", paddingLines)
 	}
 
 	return header + "\n" + content + padding + "\n" + footer

internal/ui/model_test.go

@@ -1,6 +1,7 @@
 package ui
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/Astro-Han/diffpane/internal"
@@ -249,6 +250,26 @@ func TestModelViewSmallHeightDoesNotPanic(t *testing.T) {
 	_ = model.View()
 }
 
+// TestModelViewEmptyStateFitsViewport verifies the empty-state header and footer
+// both remain visible within the terminal height instead of scrolling off-screen.
+func TestModelViewEmptyStateFitsViewport(t *testing.T) {
+	model := NewModel("repo", "/tmp/repo", "sha", nil)
+	model.Width = 80
+	model.Height = 4
+
+	view := model.View()
+	lines := strings.Split(view, "\n")
+	if len(lines) != 4 {
+		t.Fatalf("line count = %d, want 4; view = %q", len(lines), view)
+	}
+	if !strings.Contains(lines[0], "repo") || !strings.Contains(lines[0], "watching") {
+		t.Fatalf("first line = %q, want empty-state header", lines[0])
+	}
+	if !strings.Contains(lines[3], "q quit") {
+		t.Fatalf("last line = %q, want footer", lines[3])
+	}
+}
+
 // TestModelScrollOffsetStaysWithinContent verifies repeated down-navigation does
 // not grow scroll state beyond the visible diff content.
 func TestModelScrollOffsetStaysWithinContent(t *testing.T) {