Create a vault whole in a temporary directory, then select it (closes #105)

vault.CreateVault takes the unlocker passphrase and writes the vault
directory, its metadata, long-term public key and passphrase unlocker
into a temporary directory, renames that into vaults.d once complete,
and only then makes the vault current. secret init and secret vault
create call it once instead of adding the unlocker afterwards, so a
kill part-way leaves either no vault, whose temporary directory the
next command that takes the lock deletes, or a complete one. A test
records the state directory before every change the call makes and
checks each state, and the command run again from it.

Model: opus-5-5

internal/secret/atomic_test.go

@@ -236,7 +236,7 @@ func newVaultWithSecret(
 ) *vault.Vault {
 	t.Helper()
 
-	vlt, err := vault.CreateVault(fs, stateDir, name, testMnemonicBuffer(t))
+	vlt, err := vault.CreateVault(fs, stateDir, name, testMnemonicBuffer(t), nil)
 	require.NoError(t, err)
 
 	buffer := memguard.NewBufferFromBytes([]byte(value))
@@ -353,7 +353,7 @@ func TestLongestNames(t *testing.T) {
 	fs := afero.NewOsFs()
 	name := strings.Repeat("a", longestName)
 
-	vlt, err := vault.CreateVault(fs, t.TempDir(), name, testMnemonicBuffer(t))
+	vlt, err := vault.CreateVault(fs, t.TempDir(), name, testMnemonicBuffer(t), nil)
 	require.NoError(t, err)
 
 	value := memguard.NewBufferFromBytes([]byte("long"))
@@ -647,7 +647,7 @@ func TestPassphraseUnlockerGetsKeyFirst(t *testing.T) {
 
 	// No mnemonic, and no current unlocker to get the key from
 	base := afero.NewMemMapFs()
-	_, err := vault.CreateVault(base, testVaultStateDir, testVaultName, nil)
+	_, err := vault.CreateVault(base, testVaultStateDir, testVaultName, nil, nil)
 	require.NoError(t, err)
 
 	fs := hookFs{Fs: base, before: func(_, path string) error {
@@ -679,7 +679,7 @@ func TestPassphraseUnlockerIsWholeOrAbsent(t *testing.T) {
 
 			base, stateDir := tfs.open(t)
 			vlt, err := vault.CreateVault(base, stateDir, testVaultName,
-				testMnemonicBuffer(t))
+				testMnemonicBuffer(t), nil)
 			require.NoError(t, err)
 
 			vaultDir, err := vlt.GetDirectory()
@@ -728,7 +728,7 @@ func TestPassphraseUnlockerReplacementKeepsVaultOpen(t *testing.T) {
 
 			base, stateDir := tfs.open(t)
 			vlt, err := vault.CreateVault(base, stateDir, testVaultName,
-				testMnemonicBuffer(t))
+				testMnemonicBuffer(t), nil)
 			require.NoError(t, err)
 
 			ltIdentity, err := vlt.GetOrDeriveLongTermKey()
@@ -911,7 +911,7 @@ func TestSecureEnclaveUnlockerFailureDeletesKey(t *testing.T) {
 
 	mnemonic := testMnemonicBuffer(t)
 	base := afero.NewMemMapFs()
-	_, err := vault.CreateVault(base, testVaultStateDir, testVaultName, mnemonic)
+	_, err := vault.CreateVault(base, testVaultStateDir, testVaultName, mnemonic, nil)
 	require.NoError(t, err)
 
 	// The unlocker's directory is named se-<label of its Secure Enclave key>

internal/secret/pgpunlock_test.go

@@ -330,7 +330,7 @@ func testCreatePGPUnlocker(
 	mnemonic := testMnemonicBuffer(t)
 
 	// Create a test vault directory structure
-	vlt, err := vault.CreateVault(fs, stateDir, vaultName, mnemonic)
+	vlt, err := vault.CreateVault(fs, stateDir, vaultName, mnemonic, nil)
 	if err != nil {
 		t.Fatalf("Failed to create vault: %v", err)
 	}

internal/secret/pgpunlocker_test.go

@@ -48,7 +48,7 @@ func TestCreatePGPUnlockerFailureWritesNothing(t *testing.T) {
 	installFakeGPG(t)
 
 	base := afero.NewMemMapFs()
-	vlt, err := vault.CreateVault(base, testVaultStateDir, testVaultName, nil)
+	vlt, err := vault.CreateVault(base, testVaultStateDir, testVaultName, nil, nil)
 	require.NoError(t, err)
 
 	fs := hookFs{Fs: base, before: func(_, path string) error {
@@ -87,7 +87,7 @@ func TestPGPUnlockerAddedTwiceKeepsFirst(t *testing.T) {
 
 	fs := afero.NewMemMapFs()
 	mnemonic := testMnemonicBuffer(t)
-	_, err := vault.CreateVault(fs, testVaultStateDir, testVaultName, mnemonic)
+	_, err := vault.CreateVault(fs, testVaultStateDir, testVaultName, mnemonic, nil)
 	require.NoError(t, err)
 
 	first, err := secret.CreatePGPUnlocker(