refactor(marketing): Abstract form logic into reusable SectionStep component

Reduces code duplication in the marketing page forms by creating a generic `SectionStep` component. This new component encapsulates the shared UI and logic for sections that include a title, description, and a dynamic list of fields (e.g., feature cards, pricing points).

The `FeaturesStep` component has been refactored to use this new `SectionStep`, resulting in a much cleaner and more maintainable implementation.

src/app/marketing/_components/ChallengesStep.tsx

@@ -0,0 +1,35 @@
+"use client";
+import SectionStep from "./SectionStep";
+import useChallengesStepPresenter, {
+  IChallengesStepFields,
+} from "./useChallengesStepPresenter";
+
+const ChallengesStep = () => {
+  const {
+    errors,
+    handleSubmit,
+    onSubmit,
+    register,
+    fields,
+    append,
+    remove,
+    control,
+  } = useChallengesStepPresenter();
+  return (
+    <SectionStep<IChallengesStepFields>
+      title="Challenges"
+      fields={fields}
+      handleSubmit={handleSubmit}
+      onSubmit={onSubmit}
+      register={register}
+      errors={errors}
+      append={append}
+      remove={remove}
+      control={control}
+      fieldName="challenges"
+      defaultValues={{ icon: "", title: "", description: "" }}
+    />
+  );
+};
+
+export default ChallengesStep;