This commit introduces a 'Contact Sales' modal on the web development page, allowing users to inquire about specific service plans.
- The pricing plan buttons now trigger this modal, pre-filled with the selected plan's details.
- Users can add custom remarks to their inquiry.
- On submission, a pre-formatted message is generated and opened in WhatsApp using a new `useWhatsAppMsgSender` composable.
- Adds `NUXT_PUBLIC_WHATSAPP_NUMBER` to the runtime configuration.
- Refactors content validation by introducing Zod schemas for `PricingPlan` and `Button` props to improve type safety.
- Adds new i18n keys for the modal interface and message templates.
This commit introduces internationalization (i18n) support by integrating the `@nuxtjs/i18n` module. It configures English (en) and
Simplified Chinese (zh-CN) locales, adds a language selector to the header, and internationalizes the index page content using
translation files.
