fix(config): prevent panic on non-struct reflection

Add guard check in findFieldByTagWithMeta to validate input is a
struct before calling NumField(). Prevents panic when function is
called with non-struct types.

Add comprehensive test coverage for string, int, bool, slice, and
map types to verify guard behavior.

Author: kichristensen

pkg/config/setter.go

@@ -52,6 +52,10 @@ func findFieldByTag(v reflect.Value, name string) (reflect.Value, error) {
 
 // findFieldByTagWithMeta finds a struct field and returns both the value and StructField metadata
 func findFieldByTagWithMeta(v reflect.Value, t reflect.Type, name string) (reflect.Value, reflect.StructField, error) {
+	if v.Kind() != reflect.Struct {
+		return reflect.Value{}, reflect.StructField{}, fmt.Errorf("expected struct, got %s", v.Kind())
+	}
+
 	for i := 0; i < v.NumField(); i++ {
 		field := t.Field(i)
 

pkg/config/setter_test.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -276,3 +277,28 @@ func TestSetConfigValue_DomainValidation_Verbosity(t *testing.T) {
 		})
 	}
 }
+
+func TestFindFieldByTagWithMeta_NonStructValue(t *testing.T) {
+	// Test that findFieldByTagWithMeta returns an error when given a non-struct value
+	// This prevents a panic from calling NumField() on non-struct types
+	tests := []struct {
+		name  string
+		value interface{}
+	}{
+		{"string", "test"},
+		{"int", 42},
+		{"bool", true},
+		{"slice", []string{"a", "b"}},
+		{"map", map[string]string{"key": "value"}},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			v := reflect.ValueOf(tt.value)
+			typ := v.Type()
+			_, _, err := findFieldByTagWithMeta(v, typ, "anyfield")
+			require.Error(t, err)
+			assert.Contains(t, err.Error(), "expected struct")
+		})
+	}
+}