Add shop-chat push notifications and a "send shop to users" endpoint

- shop-chat messages (buyer <-> shop owner) never sent any push notification
  at all — sendShopChatPushNotification (chatHelpers.js) now fires on every
  send, mirroring the existing regular-chat push path; data payload carries
  shop_id/buyer_id/sender_role so clients can route directly to the thread
- New POST /shops/:id/send, mirroring the existing shop-product send
  endpoint — lets a user share a shop itself (not just one product) into a
  regular chat message as a sharedShop payload

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

routes/application/shops/index.js

@@ -11,7 +11,8 @@ const {
   updateShopLocation,
   updateShopContact,
   toggleShopFollow,
-  submitShop
+  submitShop,
+  sendShopToUsers
 } = require('../../../controllers/application/shops/shopController')
 const {
   getCart,
@@ -48,5 +49,6 @@ router.patch('/:id/location', [blockCheck], updateShopLocation)
 router.patch('/:id/contact', [blockCheck], updateShopContact)
 router.post('/:id/follow', [blockCheck], toggleShopFollow)
 router.post('/:id/submit', [blockCheck], submitShop)
+router.post('/:id/send', [blockCheck], sendShopToUsers)
 
 module.exports = router