feat: Voice Channel (#11602)

Enables agents to initiate outbound calls and receive incoming calls
directly from the Chatwoot dashboard, with Twilio as the initial
provider.

Fixes:  #11481 

> This is an integration branch to ensure features works well and might
be often broken on down merges, we will be extracting the
functionalities via smaller PRs into develop

- [x] https://github.com/chatwoot/chatwoot/pull/11775
- [x] https://github.com/chatwoot/chatwoot/pull/12218
- [x] https://github.com/chatwoot/chatwoot/pull/12243
- [x] https://github.com/chatwoot/chatwoot/pull/12268
- [x] https://github.com/chatwoot/chatwoot/pull/12361
- [x]  https://github.com/chatwoot/chatwoot/pull/12782
- [x] #13064
- [ ] Ability for agents to join the inbound calls ( included in this PR
)

---------

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

app/javascript/dashboard/components-next/Contacts/VoiceCallButton.vue

@@ -6,6 +6,7 @@ import { useMapGetter, useStore } from 'dashboard/composables/store';
 import { INBOX_TYPES } from 'dashboard/helper/inbox';
 import { useAlert } from 'dashboard/composables';
 import { frontendURL, conversationUrl } from 'dashboard/helper/URLHelper';
+import { useCallsStore } from 'dashboard/stores/calls';
 
 import Button from 'dashboard/components-next/button/Button.vue';
 import Dialog from 'dashboard/components-next/dialog/Dialog.vue';
@@ -67,6 +68,17 @@ const startCall = async inboxId => {
       contactId: props.contactId,
       inboxId,
     });
+    const { call_sid: callSid, conversation_id: conversationId } = response;
+
+    // Add call to store immediately so widget shows
+    const callsStore = useCallsStore();
+    callsStore.addCall({
+      callSid,
+      conversationId,
+      inboxId,
+      callDirection: 'outbound',
+    });
+
     useAlert(t('CONTACT_PANEL.CALL_INITIATED'));
     navigateToConversation(response?.conversation_id);
   } catch (error) {