feat: persist and dispatch client command input

internal/client/supervisor/windows/environment_test.go

@@ -0,0 +1,36 @@
+package windows
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestEnvironmentOverlayIsCaseInsensitiveAndDeterministic_HP_WINENV_01(t *testing.T) {
+	t.Parallel()
+	base := map[string]string{"Path": `C:\Windows`, "TEMP": `C:\Temp`, "=C:": `C:\Windows`}
+	overrides := map[string]string{"PATH": `C:\Pinned`, "Name": "rvbox"}
+	entries, err := MergeEnvironment(base, overrides)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(entries) != 4 || entries[0].Folded != "=C:" || entries[1].Folded != "NAME" || entries[2].Folded != "PATH" || entries[2].Value != `C:\Pinned` {
+		t.Fatalf("merged entries = %#v", entries)
+	}
+	block, err := BuildEnvironmentBlock(base, overrides)
+	if err != nil || len(block) == 0 || block[len(block)-1] != 0 || block[len(block)-2] != 0 {
+		t.Fatalf("environment block = len=%d err=%v", len(block), err)
+	}
+}
+
+func TestEnvironmentOverlayRejectsMalformedAndDuplicateBase_BH_WINENV_01(t *testing.T) {
+	t.Parallel()
+	if _, err := MergeEnvironment(map[string]string{"Path": "one", "PATH": "two"}, nil); !errors.Is(err, ErrDuplicateEnvironmentKey) {
+		t.Fatalf("duplicate base error = %v", err)
+	}
+	if _, err := MergeEnvironment(nil, map[string]string{"BAD=KEY": "value"}); !errors.Is(err, ErrInvalidEnvironmentKey) {
+		t.Fatalf("invalid override key error = %v", err)
+	}
+	if _, err := MergeEnvironment(nil, map[string]string{"NUL": "bad\x00value"}); !errors.Is(err, ErrInvalidEnvironmentValue) {
+		t.Fatalf("invalid override value error = %v", err)
+	}
+}