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>

spec/controllers/api/v1/accounts/inboxes_controller_spec.rb

@@ -904,4 +904,80 @@ RSpec.describe 'Inboxes API', type: :request do
       end
     end
   end
+
+  describe 'POST /api/v1/accounts/{account.id}/inboxes/:id/sync_templates' do
+    let(:whatsapp_channel) do
+      create(:channel_whatsapp, account: account, provider: 'whatsapp_cloud', sync_templates: false, validate_provider_config: false)
+    end
+    let(:whatsapp_inbox) { create(:inbox, account: account, channel: whatsapp_channel) }
+    let(:non_whatsapp_inbox) { create(:inbox, account: account) }
+
+    context 'when it is an unauthenticated user' do
+      it 'returns unauthorized' do
+        post "/api/v1/accounts/#{account.id}/inboxes/#{whatsapp_inbox.id}/sync_templates"
+
+        expect(response).to have_http_status(:unauthorized)
+      end
+    end
+
+    context 'when it is an authenticated agent' do
+      it 'returns unauthorized for agent' do
+        post "/api/v1/accounts/#{account.id}/inboxes/#{whatsapp_inbox.id}/sync_templates",
+             headers: agent.create_new_auth_token,
+             as: :json
+
+        expect(response).to have_http_status(:unauthorized)
+      end
+    end
+
+    context 'when it is an authenticated administrator' do
+      context 'with WhatsApp inbox' do
+        it 'successfully initiates template sync' do
+          expect(Channels::Whatsapp::TemplatesSyncJob).to receive(:perform_later).with(whatsapp_channel)
+
+          post "/api/v1/accounts/#{account.id}/inboxes/#{whatsapp_inbox.id}/sync_templates",
+               headers: admin.create_new_auth_token,
+               as: :json
+
+          expect(response).to have_http_status(:success)
+          json_response = response.parsed_body
+          expect(json_response['message']).to eq('Template sync initiated successfully')
+        end
+
+        it 'handles job errors gracefully' do
+          allow(Channels::Whatsapp::TemplatesSyncJob).to receive(:perform_later).and_raise(StandardError, 'Job failed')
+
+          post "/api/v1/accounts/#{account.id}/inboxes/#{whatsapp_inbox.id}/sync_templates",
+               headers: admin.create_new_auth_token,
+               as: :json
+
+          expect(response).to have_http_status(:internal_server_error)
+          json_response = response.parsed_body
+          expect(json_response['error']).to eq('Job failed')
+        end
+      end
+
+      context 'with non-WhatsApp inbox' do
+        it 'returns unprocessable entity error' do
+          post "/api/v1/accounts/#{account.id}/inboxes/#{non_whatsapp_inbox.id}/sync_templates",
+               headers: admin.create_new_auth_token,
+               as: :json
+
+          expect(response).to have_http_status(:unprocessable_entity)
+          json_response = response.parsed_body
+          expect(json_response['error']).to eq('Template sync is only available for WhatsApp channels')
+        end
+      end
+
+      context 'with non-existent inbox' do
+        it 'returns not found error' do
+          post "/api/v1/accounts/#{account.id}/inboxes/999999/sync_templates",
+               headers: admin.create_new_auth_token,
+               as: :json
+
+          expect(response).to have_http_status(:not_found)
+        end
+      end
+    end
+  end
 end