Fix intrange and G101 linting issues

- Convert for loops to use Go 1.22+ integer ranges in generate.go and helpers.go
- Disable G101 false positives for test vectors and environment variable names
- Add file-level gosec disable for bip85_test.go containing BIP85 test vectors
- Add targeted nolint comments for legitimate test data and constants

internal/cli/cli.go

@@ -14,54 +14,54 @@ import (
 )
 
 // Global scanner for consistent stdin reading
-var stdinScanner *bufio.Scanner
+var stdinScanner *bufio.Scanner //nolint:gochecknoglobals // Needed for consistent stdin handling
 
-// CLIInstance encapsulates all CLI functionality and state
-type CLIInstance struct {
+// Instance encapsulates all CLI functionality and state
+type Instance struct {
 	fs       afero.Fs
 	stateDir string
 	cmd      *cobra.Command
 }
 
 // NewCLIInstance creates a new CLI instance with the real filesystem
-func NewCLIInstance() *CLIInstance {
+func NewCLIInstance() *Instance {
 	fs := afero.NewOsFs()
 	stateDir := secret.DetermineStateDir("")
-	return &CLIInstance{
+	return &Instance{
 		fs:       fs,
 		stateDir: stateDir,
 	}
 }
 
 // NewCLIInstanceWithFs creates a new CLI instance with the given filesystem (for testing)
-func NewCLIInstanceWithFs(fs afero.Fs) *CLIInstance {
+func NewCLIInstanceWithFs(fs afero.Fs) *Instance {
 	stateDir := secret.DetermineStateDir("")
-	return &CLIInstance{
+	return &Instance{
 		fs:       fs,
 		stateDir: stateDir,
 	}
 }
 
 // NewCLIInstanceWithStateDir creates a new CLI instance with custom state directory (for testing)
-func NewCLIInstanceWithStateDir(fs afero.Fs, stateDir string) *CLIInstance {
-	return &CLIInstance{
+func NewCLIInstanceWithStateDir(fs afero.Fs, stateDir string) *Instance {
+	return &Instance{
 		fs:       fs,
 		stateDir: stateDir,
 	}
 }
 
 // SetFilesystem sets the filesystem for this CLI instance (for testing)
-func (cli *CLIInstance) SetFilesystem(fs afero.Fs) {
+func (cli *Instance) SetFilesystem(fs afero.Fs) {
 	cli.fs = fs
 }
 
 // SetStateDir sets the state directory for this CLI instance (for testing)
-func (cli *CLIInstance) SetStateDir(stateDir string) {
+func (cli *Instance) SetStateDir(stateDir string) {
 	cli.stateDir = stateDir
 }
 
 // GetStateDir returns the state directory for this CLI instance
-func (cli *CLIInstance) GetStateDir() string {
+func (cli *Instance) GetStateDir() string {
 	return cli.stateDir
 }
 
@@ -77,7 +77,7 @@ func getStdinScanner() *bufio.Scanner {
 // Uses a shared scanner to avoid buffering issues between multiple calls
 func readLineFromStdin(prompt string) (string, error) {
 	// Check if stderr is a terminal - if not, we can't prompt interactively
-	if !term.IsTerminal(int(syscall.Stderr)) {
+	if !term.IsTerminal(syscall.Stderr) {
 		return "", fmt.Errorf("cannot prompt for input: stderr is not a terminal (running in non-interactive mode)")
 	}