feat(voice): WhatsApp calling UI — inbox toggle, call widget, badges

Frontend for WhatsApp WABA calling: calling status toggle in inbox settings, WhatsApp Call channel tile, voice badges, call widget redesign, and conversation header call button.

app/javascript/dashboard/i18n/locale/en/conversation.json

@@ -83,6 +83,7 @@
       "NO_ANSWER_OUTBOUND_SUBTEXT": "Contact didn't pick up",
       "MISSED_CALL": "Missed call",
       "MISSED_CALL_INBOUND_SUBTEXT": "No agent picked up",
+      "MISSED_CALL_DECLINED_BY": "Declined by {agentName}",
       "CALL_ENDED": "Call ended",
       "NOT_ANSWERED_YET": "Not answered yet",
       "CALLING": "Calling…",
@@ -107,6 +108,8 @@
       "SNOOZED_UNTIL_NEXT_REPLY": "Snoozed until next reply",
       "WHATSAPP_CALL": "Start WhatsApp call",
       "WHATSAPP_CALL_FAILED": "Could not start the WhatsApp call.",
+      "VOICE_CALL": "Start call",
+      "VOICE_CALL_FAILED": "Could not start the call.",
       "WHATSAPP_CALL_PERMISSION_REQUESTED": "Sent a call permission request to the contact. Try again once they accept.",
       "WHATSAPP_CALL_PERMISSION_PENDING": "Call permission request already sent recently. Try again once the contact accepts.",
       "SLA_STATUS": {

app/javascript/dashboard/i18n/locale/en/inboxMgmt.json

@@ -308,6 +308,7 @@
           "AUTH_PROCESSING": "Authenticating with Meta",
           "WAITING_FOR_BUSINESS_INFO": "Please complete business setup in the Meta window...",
           "PROCESSING": "Setting up your WhatsApp Business Account",
+          "ENABLING_CALLING": "Enabling WhatsApp Calling on your number…",
           "LOADING_SDK": "Loading Facebook SDK...",
           "CANCELLED": "WhatsApp Signup was cancelled",
           "SUCCESS_TITLE": "WhatsApp Business Account Connected!",
@@ -317,7 +318,8 @@
           "AUTH_NOT_COMPLETED": "Authentication not completed. Please restart the process.",
           "SUCCESS_FALLBACK": "WhatsApp Business Account has been successfully configured",
           "MANUAL_FALLBACK": "If your number is already connected to the WhatsApp Business Platform (API), or if you’re a tech provider onboarding your own number, please use the {link} flow",
-          "MANUAL_LINK_TEXT": "manual setup flow"
+          "MANUAL_LINK_TEXT": "manual setup flow",
+          "CALLING_ENABLE_FAILED": "Your WhatsApp inbox is ready, but voice calling couldn't be turned on — this number isn't enrolled in the WhatsApp Business Calling API yet. Reach out to Meta or your WhatsApp Business Solution Provider to onboard it, then turn calling on from the inbox's Calls settings."
         },
         "API": {
           "ERROR_MESSAGE": "We were not able to save the WhatsApp channel"
@@ -465,6 +467,10 @@
             "TITLE": "WhatsApp",
             "DESCRIPTION": "Support your customers on WhatsApp"
           },
+          "WHATSAPP_CALL": {
+            "TITLE": "WhatsApp Call",
+            "DESCRIPTION": "Take voice calls on your WhatsApp number"
+          },
           "EMAIL": {
             "TITLE": "Email",
             "DESCRIPTION": "Connect with Gmail, Outlook, or other providers"
@@ -654,6 +660,7 @@
         "LABEL": "Enable WhatsApp Calling",
         "DESCRIPTION": "Allow agents to receive and place WhatsApp Cloud calls on this inbox. Customers can call this business number directly from WhatsApp."
       },
+      "ENABLE_FAILED": "Voice calling couldn't be turned on for this number — it isn't enrolled in the WhatsApp Business Calling API yet. Reach out to Meta or your WhatsApp Business Solution Provider to onboard it, then try again.",
       "PHONE_NUMBER": {
         "LABEL": "Business phone number",
         "HELP_TEXT": "WhatsApp number that customers will call."