fix: resolve all nlreturn linter errors

Add blank lines before return statements in all files to satisfy
the nlreturn linter. This improves code readability by providing
visual separation before return statements.

Changes made across 24 files:
- internal/cli/*.go
- internal/secret/*.go
- internal/vault/*.go
- pkg/agehd/agehd.go
- pkg/bip85/bip85.go

All 143 nlreturn issues have been resolved.

pkg/bip85/bip85.go

@@ -28,13 +28,13 @@ const (
 	BIP85_KEY_HMAC_KEY = "bip-entropy-from-k" //nolint:revive // ALL_CAPS used for BIP85 constants
 
 	// Application numbers
-	AppBIP39  = 39 // BIP39 mnemonics
-	AppHDWIF = 2 // WIF for Bitcoin Core
-	AppXPRV = 32 // Extended private key
-	APP_HEX    = 128169 //nolint:revive // ALL_CAPS used for BIP85 constants
-	APP_PWD64  = 707764 // Base64 passwords //nolint:revive // ALL_CAPS used for BIP85 constants
-	AppPWD85 = 707785 // Base85 passwords
-	APP_RSA    = 828365 //nolint:revive // ALL_CAPS used for BIP85 constants
+	AppBIP39  = 39     // BIP39 mnemonics
+	AppHDWIF  = 2      // WIF for Bitcoin Core
+	AppXPRV   = 32     // Extended private key
+	APP_HEX   = 128169 //nolint:revive // ALL_CAPS used for BIP85 constants
+	APP_PWD64 = 707764 // Base64 passwords //nolint:revive // ALL_CAPS used for BIP85 constants
+	AppPWD85  = 707785 // Base85 passwords
+	APP_RSA   = 828365 //nolint:revive // ALL_CAPS used for BIP85 constants
 )
 
 // Version bytes for extended keys
@@ -178,7 +178,7 @@ func DeriveBIP39Entropy(masterKey *hdkeychain.ExtendedKey, language, words, inde
 		words21 = 21 // 224 bits of entropy
 		words24 = 24 // 256 bits of entropy
 	)
-	
+
 	var bits int
 	switch words {
 	case words12: