feat: Add manual WhatsApp templates sync with UI (#12007)

Fixes https://github.com/chatwoot/chatwoot/issues/9600

**Summary**
- Added manual WhatsApp templates sync functionality accessible via UI
- Added refresh button in both inbox settings and template picker modal
- Enhanced template picker to always show for WhatsApp Cloud channels
(even when empty)


**Preview**

<img width="1456" height="798" alt="CleanShot 2025-07-22 at 14 15 28@2x"
src="https://github.com/user-attachments/assets/8a04ff26-61fa-42ee-a1b8-5e06433ae6e0"
/>


<img width="2376" height="1574" alt="CleanShot 2025-07-22 at 14 19
24@2x"
src="https://github.com/user-attachments/assets/1c772034-04ff-484d-88dd-ca8123e93065"
/>

---------

Co-authored-by: iamsivin <iamsivin@gmail.com>

app/javascript/dashboard/api/specs/inboxes.spec.js

@@ -12,6 +12,7 @@ describe('#InboxesAPI', () => {
     expect(inboxesAPI).toHaveProperty('getCampaigns');
     expect(inboxesAPI).toHaveProperty('getAgentBot');
     expect(inboxesAPI).toHaveProperty('setAgentBot');
+    expect(inboxesAPI).toHaveProperty('syncTemplates');
   });
 
   describe('API calls', () => {
@@ -40,5 +41,12 @@ describe('#InboxesAPI', () => {
       inboxesAPI.deleteInboxAvatar(2);
       expect(axiosMock.delete).toHaveBeenCalledWith('/api/v1/inboxes/2/avatar');
     });
+
+    it('#syncTemplates', () => {
+      inboxesAPI.syncTemplates(2);
+      expect(axiosMock.post).toHaveBeenCalledWith(
+        '/api/v1/inboxes/2/sync_templates'
+      );
+    });
   });
 });