fix: convert for loops to Go 1.22+ integer range syntax (intrange)

Convert traditional for loops to use the new Go 1.22+ integer range syntax:
- for i := 0; i < n; i++ → for i := range n (when index is used)
- for i := 0; i < n; i++ → for range n (when index is not used)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

internal/cli/integration_test.go

@@ -1658,7 +1658,7 @@ func test25ConcurrentOperations(t *testing.T, testMnemonic string, runSecret fun
 	const numReaders = 5
 	errors := make(chan error, numReaders)
 
-	for i := 0; i < numReaders; i++ {
+	for i := range numReaders {
 		go func(id int) {
 			output, err := runSecretWithEnv(map[string]string{
 				"SB_SECRET_MNEMONIC": testMnemonic,
@@ -1674,7 +1674,7 @@ func test25ConcurrentOperations(t *testing.T, testMnemonic string, runSecret fun
 	}
 
 	// Wait for all readers
-	for i := 0; i < numReaders; i++ {
+	for range numReaders {
 		err := <-errors
 		assert.NoError(t, err, "concurrent read should succeed")
 	}