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/cmd/hostkeeper/edit_test.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestEditCommandExists(t *testing.T) {
+	if editCmd == nil {
+		t.Fatal("editCmd should not be nil")
+	}
+
+	if editCmd.Use != "edit <host-name-or-id>" {
+		t.Errorf("expected Use 'edit <host-name-or-id>', got '%s'", editCmd.Use)
+	}
+
+	if editCmd.Short == "" {
+		t.Error("Short description should not be empty")
+	}
+}
+
+func TestEditCommandFlags(t *testing.T) {
+	expectedFlags := []string{"host", "port", "user", "password", "key", "auth-type", "group", "tags", "notes", "name"}
+	for _, flagName := range expectedFlags {
+		if editCmd.Flags().Lookup(flagName) == nil {
+			t.Errorf("flag '%s' should be defined", flagName)
+		}
+	}
+}
+
+func TestEditArgs(t *testing.T) {
+	if editCmd.Args == nil {
+		t.Error("Args validator should not be nil")
+	}
+}