refactor: move V1 code into v1/ subdirectory

- git mv cmd/ internal/ pkg/ test/ go.mod go.sum Makefile build.sh docs/ v1/
- Create v1/README.md with V1 documentation
- Update root README for V1 + V2 structure
- V1 still builds (cd v1 && go build ./cmd/hostkeeper) and 105 tests pass
- Root is now clean for V2 development

v1/test/tui/responsive_test.go

@@ -0,0 +1,92 @@
+package tui_test
+
+import (
+	"testing"
+
+	"git.tukangketik.id/swanadiva/hostkeeper/pkg/tui"
+)
+
+// 5.1 WrapFooter short — single line
+func TestWrapFooterShort(t *testing.T) {
+	result := tui.WrapFooter("short footer", 80)
+	if result != "short footer" {
+		t.Errorf("WrapFooter short = %q, want %q", result, "short footer")
+	}
+}
+
+// 5.2 WrapFooter long — multi-line
+func TestWrapFooterLong(t *testing.T) {
+	// Footer longer than 30 chars should wrap
+	footer := "key1  key2  key3  key4  key5  key6  key7  key8  key9  key10"
+	result := tui.WrapFooter(footer, 30)
+	if result == footer {
+		t.Error("WrapFooter should wrap long footer")
+	}
+}
+
+// 5.3 WrapFooter empty
+func TestWrapFooterEmpty(t *testing.T) {
+	result := tui.WrapFooter("", 80)
+	if result != "" {
+		t.Errorf("WrapFooter empty = %q, want %q", result, "")
+	}
+}
+
+// 5.4 ClampWidth over max
+func TestClampWidthOver(t *testing.T) {
+	result := tui.ClampWidth(200, 80)
+	if result > 74 { // 80 - 6 (boxOverhead)
+		t.Errorf("ClampWidth(200, 80) = %d, should be <= 74", result)
+	}
+}
+
+// 5.5 ClampWidth under min
+func TestClampWidthUnder(t *testing.T) {
+	result := tui.ClampWidth(5, 80)
+	if result < 20 {
+		t.Errorf("ClampWidth(5, 80) = %d, should be >= 20", result)
+	}
+}
+
+// 5.6 ClampWidth in range
+func TestClampWidthInRange(t *testing.T) {
+	result := tui.ClampWidth(50, 80)
+	if result != 50 {
+		t.Errorf("ClampWidth(50, 80) = %d, want 50", result)
+	}
+}
+
+// 5.7 TruncateStr short
+func TestTruncateStrShort(t *testing.T) {
+	result := tui.TruncateStr("hello", 20)
+	if result != "hello" {
+		t.Errorf("TruncateStr short = %q, want %q", result, "hello")
+	}
+}
+
+// 5.8 TruncateStr long
+func TestTruncateStrLong(t *testing.T) {
+	result := tui.TruncateStr("this is a very long string that should be truncated", 10)
+	if result == "this is a very long string that should be truncated" {
+		t.Error("TruncateStr should truncate long string")
+	}
+	if len(result) > 12 { // 11 content + 1 ellipsis
+		t.Errorf("TruncateStr result too long: %d chars", len(result))
+	}
+}
+
+// 5.9 TruncateStr empty
+func TestTruncateStrEmpty(t *testing.T) {
+	result := tui.TruncateStr("", 20)
+	if result != "" {
+		t.Errorf("TruncateStr empty = %q, want %q", result, "")
+	}
+}
+
+// 5.10 TruncateStr unicode
+func TestTruncateStrUnicode(t *testing.T) {
+	result := tui.TruncateStr("こんにちは世界", 5)
+	if result == "こんにちは世界" {
+		t.Error("TruncateStr should truncate unicode string")
+	}
+}