feat(webDev): add inquiry modal for pricing plans

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.

i18n/locales/en-US/common.json

@@ -52,6 +52,11 @@
           }
         }
       }
+    },
+    "button": {
+      "cancel": "Cancel",
+      "submit": "Submit",
+      "saving": "Saving..."
     }
   }
 }

i18n/locales/en-US/index.json

@@ -4,5 +4,15 @@
     "featuredProjects": {
       "viewDemo": "Visit Site"
     }
+  },
+  "webDev": {
+    "know_more_description": "I need to know more about the pricing and service about {plan} plan.",
+    "know_more_title": "Know more {plan} plan",
+    "contact_intro": "Hi — I'd like to learn more about {service} {plan} plan.",
+    "which_provides": "Which provides:",
+    "extra_remarks_title": "Besides that, I'd like to add:",
+    "remarks_placeholder": "Enter your remarks or requirements, one per line",
+    "loading_plan": "Loading plan...",
+    "whatsapp_message": "Hello! I’m interested in the **{plan}** plan under your **{service}** service.\n\nHere are the plan details:\n💰 Price: {price}\n✨ Key Features:\n{featureList}\nAdditionally, I would like to request:\n{remarkList}\nPlease provide more detailed information. Thank you!"
   }
 }

i18n/locales/zh-CN/common.json

@@ -52,6 +52,11 @@
           }
         }
       }
+    },
+    "button": {
+      "cancel": "取消",
+      "submit": "提交",
+      "saving": "保存..."
     }
   }
 }

i18n/locales/zh-CN/index.json

@@ -4,5 +4,15 @@
     "featuredProjects": {
       "viewDemo": "访问页面"
     }
+  },
+  "webDev": {
+    "know_more_description": "我需要了解有关 {plan} 的定价和服务的更多信息。",
+    "know_more_title": "了解更多{plan}",
+    "contact_intro": "你好——我想了解更多关于 {service} {plan}",
+    "which_provides": "其中包含：",
+    "extra_remarks_title": "除此之外，我还想补充：",
+    "remarks_placeholder": "输入您的备注或要求，每行一个",
+    "loading_plan": "配套加载中。。。",
+    "whatsapp_message": "您好！我对您的【{service}】服务中的【{plan}】方案感兴趣。\n\n方案详情：\n💰 价格：{price}\n✨ 主要功能：\n{featureList}\n另外我还需要：\n{remarkList}\n请提供更多详细信息，谢谢！"
   }
 }