fix: replace remaining os.Setenv with t.Setenv in tests

Replace all os.Setenv calls with t.Setenv in test functions to ensure
proper test environment cleanup and better test isolation. This leaves
only legitimate application code and helper functions using os.Setenv.

internal/cli/cli_test.go

@@ -37,19 +37,9 @@ func TestCLIInstanceWithFs(t *testing.T) {
 func TestDetermineStateDir(t *testing.T) {
 	// Test the determineStateDir function from the secret package
 
-	// Save original environment and restore it after test
-	originalStateDir := os.Getenv(secret.EnvStateDir)
-	defer func() {
-		if originalStateDir == "" {
-			os.Unsetenv(secret.EnvStateDir)
-		} else {
-			os.Setenv(secret.EnvStateDir, originalStateDir)
-		}
-	}()
-
 	// Test with environment variable set
 	testEnvDir := "/test-env-dir"
-	os.Setenv(secret.EnvStateDir, testEnvDir)
+	t.Setenv(secret.EnvStateDir, testEnvDir)
 
 	stateDir := secret.DetermineStateDir("")
 	if stateDir != testEnvDir {

internal/secret/passphrase_test.go

@@ -131,18 +131,8 @@ func TestPassphraseUnlockerWithRealFS(t *testing.T) {
 		}
 	})
 
-	// Save original environment variables and set test ones
-	oldPassphrase := os.Getenv(secret.EnvUnlockPassphrase)
-	os.Setenv(secret.EnvUnlockPassphrase, testPassphrase)
-
-	// Clean up after test
-	defer func() {
-		if oldPassphrase != "" {
-			os.Setenv(secret.EnvUnlockPassphrase, oldPassphrase)
-		} else {
-			os.Unsetenv(secret.EnvUnlockPassphrase)
-		}
-	}()
+	// Set test environment variable (cleaned up automatically)
+	t.Setenv(secret.EnvUnlockPassphrase, testPassphrase)
 
 	// Test getting identity from environment variable
 	t.Run("GetIdentityFromEnv", func(t *testing.T) {

internal/secret/pgpunlock_test.go

@@ -143,20 +143,8 @@ func TestPGPUnlockerWithRealFS(t *testing.T) {
 		t.Fatalf("Failed to create GNUPGHOME: %v", err)
 	}
 
-	// Save original GNUPGHOME
-	origGnupgHome := os.Getenv("GNUPGHOME")
-
 	// Set new GNUPGHOME
-	os.Setenv("GNUPGHOME", gnupgHomeDir)
-
-	// Clean up environment after test
-	defer func() {
-		if origGnupgHome != "" {
-			os.Setenv("GNUPGHOME", origGnupgHome)
-		} else {
-			os.Unsetenv("GNUPGHOME")
-		}
-	}()
+	t.Setenv("GNUPGHOME", gnupgHomeDir)
 
 	// Test passphrase for GPG key
 	testPassphrase := "test123"
@@ -224,15 +212,7 @@ Passphrase: ` + testPassphrase + `
 	t.Logf("Generated GPG fingerprint: %s", fingerprint)
 
 	// Set the GPG_AGENT_INFO to empty to ensure gpg-agent doesn't interfere
-	oldAgentInfo := os.Getenv("GPG_AGENT_INFO")
-	os.Setenv("GPG_AGENT_INFO", "")
-	defer func() {
-		if oldAgentInfo != "" {
-			os.Setenv("GPG_AGENT_INFO", oldAgentInfo)
-		} else {
-			os.Unsetenv("GPG_AGENT_INFO")
-		}
-	}()
+	t.Setenv("GPG_AGENT_INFO", "")
 
 	// Use the real filesystem
 	fs := afero.NewOsFs()
@@ -240,28 +220,9 @@ Passphrase: ` + testPassphrase + `
 	// Test data
 	testMnemonic := "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
 
-	// Save original environment variable
-	oldMnemonic := os.Getenv(secret.EnvMnemonic)
-	oldGPGKeyID := os.Getenv(secret.EnvGPGKeyID)
-
 	// Set test environment variables
-	os.Setenv(secret.EnvMnemonic, testMnemonic)
-	os.Setenv(secret.EnvGPGKeyID, keyID)
-
-	// Clean up after test
-	defer func() {
-		if oldMnemonic != "" {
-			os.Setenv(secret.EnvMnemonic, oldMnemonic)
-		} else {
-			os.Unsetenv(secret.EnvMnemonic)
-		}
-
-		if oldGPGKeyID != "" {
-			os.Setenv(secret.EnvGPGKeyID, oldGPGKeyID)
-		} else {
-			os.Unsetenv(secret.EnvGPGKeyID)
-		}
-	}()
+	t.Setenv(secret.EnvMnemonic, testMnemonic)
+	t.Setenv(secret.EnvGPGKeyID, keyID)
 
 	// Set up vault structure for testing
 	stateDir := tempDir

internal/secret/secret_test.go

@@ -128,19 +128,9 @@ func TestPerSecretKeyFunctionality(t *testing.T) {
 	// Create an in-memory filesystem for testing
 	fs := afero.NewMemMapFs()
 
-	// Set up test environment variables
-	oldMnemonic := os.Getenv(EnvMnemonic)
-	defer func() {
-		if oldMnemonic == "" {
-			os.Unsetenv(EnvMnemonic)
-		} else {
-			os.Setenv(EnvMnemonic, oldMnemonic)
-		}
-	}()
-
 	// Set test mnemonic for direct encryption/decryption
 	testMnemonic := "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
-	os.Setenv(EnvMnemonic, testMnemonic)
+	t.Setenv(EnvMnemonic, testMnemonic)
 
 	// Set up a test vault structure
 	baseDir := "/test-config/berlin.sneak.pkg.secret"
@@ -312,9 +302,7 @@ func TestSecretGetValueWithEnvMnemonicUsesVaultDerivationIndex(t *testing.T) {
 
 	// Set up test mnemonic
 	testMnemonic := "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
-	originalEnv := os.Getenv(EnvMnemonic)
-	os.Setenv(EnvMnemonic, testMnemonic)
-	defer os.Setenv(EnvMnemonic, originalEnv)
+	t.Setenv(EnvMnemonic, testMnemonic)
 
 	// Create temporary directory for vaults
 	fs := afero.NewOsFs()