feat: Voice channel creation Flow (#11775)

This PR introduces a new channel type for voice conversations.

ref: #11481 

## Changes

- Add database migration for channel_voice table with phone_number and
provider_config
- Create Channel::Voice model with E.164 phone number validation and
Twilio config validation
- Add voice channel association to Account model
- Extend inbox helpers and types to support voice channels
- Add voice channel setup UI with Twilio configuration form
- Include voice channel in channel factory and list components
- Add API routes and store actions for voice channel creation
- Add comprehensive translations for voice channel management

---------

Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: iamsivin <iamsivin@gmail.com>

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

@@ -268,6 +268,46 @@
           "ERROR_MESSAGE": "We were not able to save the WhatsApp channel"
         }
       },
+      "VOICE": {
+        "TITLE": "Voice Channel",
+        "DESC": "Integrate Twilio Voice and start supporting your customers via phone calls.",
+        "PHONE_NUMBER": {
+          "LABEL": "Phone Number",
+          "PLACEHOLDER": "Enter your phone number (e.g. +1234567890)",
+          "ERROR": "Please provide a valid phone number in E.164 format (e.g. +1234567890)"
+        },
+        "TWILIO": {
+          "ACCOUNT_SID": {
+            "LABEL": "Account SID",
+            "PLACEHOLDER": "Enter your Twilio Account SID",
+            "REQUIRED": "Account SID is required"
+          },
+          "AUTH_TOKEN": {
+            "LABEL": "Auth Token",
+            "PLACEHOLDER": "Enter your Twilio Auth Token",
+            "REQUIRED": "Auth Token is required"
+          },
+          "API_KEY_SID": {
+            "LABEL": "API Key SID",
+            "PLACEHOLDER": "Enter your Twilio API Key SID",
+            "REQUIRED": "API Key SID is required"
+          },
+          "API_KEY_SECRET": {
+            "LABEL": "API Key Secret",
+            "PLACEHOLDER": "Enter your Twilio API Key Secret",
+            "REQUIRED": "API Key Secret is required"
+          },
+          "TWIML_APP_SID": {
+            "LABEL": "TwiML App SID",
+            "PLACEHOLDER": "Enter your Twilio TwiML App SID (starts with AP)",
+            "REQUIRED": "TwiML App SID is required"
+          }
+        },
+        "SUBMIT_BUTTON": "Create Voice Channel",
+        "API": {
+          "ERROR_MESSAGE": "We were not able to create the voice channel"
+        }
+      },
       "API_CHANNEL": {
         "TITLE": "API Channel",
         "DESC": "Integrate with API channel and start supporting your customers.",
@@ -789,7 +829,8 @@
       "TELEGRAM": "Telegram",
       "LINE": "Line",
       "API": "API Channel",
-      "INSTAGRAM": "Instagram"
+      "INSTAGRAM": "Instagram",
+      "VOICE": "Voice"
     }
   }
 }