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.

internal/cli/cli.go

@@ -37,6 +37,7 @@ func NewCLIInstance() *Instance {
 // NewCLIInstanceWithFs creates a new CLI instance with the given filesystem (for testing)
 func NewCLIInstanceWithFs(fs afero.Fs) *Instance {
 	stateDir := secret.DetermineStateDir("")
+
 	return &Instance{
 		fs:       fs,
 		stateDir: stateDir,