fix: Translate "None" option in agent assignment dropdown (#11060)

# Pull Request Template

## Description

This PR includes a translation update for the "None" option in the agent
assignment multi-select dropdown.

Fixes
https://linear.app/chatwoot/issue/CW-4140/none-option-in-assign-agent-multi-select-is-not-translated

## Type of change

- [x] Bug fix (non-breaking change which fixes an issue)

## How Has This Been Tested?

**Test cases**
1. Check in conversation sidebar
2. Check in command bar
3. Check in participation dropdown


## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

app/javascript/dashboard/composables/spec/useAgentsList.spec.js

@@ -5,9 +5,26 @@ import { useMapGetter } from 'dashboard/composables/store';
 import { allAgentsData, formattedAgentsData } from './fixtures/agentFixtures';
 import * as agentHelper from 'dashboard/helper/agentHelper';
 
+// Mock vue-i18n
+vi.mock('vue-i18n', () => ({
+  useI18n: () => ({
+    t: key => (key === 'AGENT_MGMT.MULTI_SELECTOR.LIST.NONE' ? 'None' : key),
+  }),
+}));
+
 vi.mock('dashboard/composables/store');
 vi.mock('dashboard/helper/agentHelper');
 
+// Create a mock None agent
+const mockNoneAgent = {
+  confirmed: true,
+  name: 'None',
+  id: 0,
+  role: 'agent',
+  account_id: 0,
+  email: 'None',
+};
+
 const mockUseMapGetter = (overrides = {}) => {
   const defaultGetters = {
     getCurrentUser: ref(allAgentsData[0]),
@@ -28,14 +45,6 @@ describe('useAgentsList', () => {
     agentHelper.getSortedAgentsByAvailability.mockReturnValue(
       formattedAgentsData.slice(1)
     );
-    agentHelper.getCombinedAgents.mockImplementation(
-      (agents, includeNone, isAgentSelected) => {
-        if (includeNone && isAgentSelected) {
-          return [agentHelper.createNoneAgent, ...agents];
-        }
-        return agents;
-      }
-    );
 
     mockUseMapGetter();
   });
@@ -44,24 +53,26 @@ describe('useAgentsList', () => {
     const { agentsList, assignableAgents } = useAgentsList();
 
     expect(assignableAgents.value).toEqual(allAgentsData);
-    expect(agentsList.value).toEqual([
-      agentHelper.createNoneAgent,
-      ...formattedAgentsData.slice(1),
-    ]);
+    expect(agentsList.value[0]).toEqual(mockNoneAgent);
+    expect(agentsList.value.length).toBe(
+      formattedAgentsData.slice(1).length + 1
+    );
   });
 
   it('includes None agent when includeNoneAgent is true', () => {
     const { agentsList } = useAgentsList(true);
 
-    expect(agentsList.value[0]).toEqual(agentHelper.createNoneAgent);
-    expect(agentsList.value.length).toBe(formattedAgentsData.length);
+    expect(agentsList.value[0]).toEqual(mockNoneAgent);
+    expect(agentsList.value.length).toBe(
+      formattedAgentsData.slice(1).length + 1
+    );
   });
 
   it('excludes None agent when includeNoneAgent is false', () => {
     const { agentsList } = useAgentsList(false);
 
-    expect(agentsList.value[0]).not.toEqual(agentHelper.createNoneAgent);
-    expect(agentsList.value.length).toBe(formattedAgentsData.length - 1);
+    expect(agentsList.value[0].id).not.toBe(0);
+    expect(agentsList.value.length).toBe(formattedAgentsData.slice(1).length);
   });
 
   it('handles empty assignable agents', () => {
@@ -73,7 +84,7 @@ describe('useAgentsList', () => {
     const { agentsList, assignableAgents } = useAgentsList();
 
     expect(assignableAgents.value).toEqual([]);
-    expect(agentsList.value).toEqual([agentHelper.createNoneAgent]);
+    expect(agentsList.value).toEqual([mockNoneAgent]);
   });
 
   it('handles missing inbox_id', () => {
@@ -86,6 +97,6 @@ describe('useAgentsList', () => {
     const { agentsList, assignableAgents } = useAgentsList();
 
     expect(assignableAgents.value).toEqual([]);
-    expect(agentsList.value).toEqual([agentHelper.createNoneAgent]);
+    expect(agentsList.value).toEqual([mockNoneAgent]);
   });
 });