feat: Allow removing labels via conversation context menu (#13525)

# Pull Request Template

## Description

This PR adds support for removing labels from the conversation card
context menu. Assigned labels now show a checkmark, and clicking an
already-selected label will remove it.

Fixes
https://linear.app/chatwoot/issue/CW-6400/allow-removing-labels-directly-from-the-right-click-menu
https://github.com/chatwoot/chatwoot/issues/13367
## Type of change

- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?

**Screencast**


https://github.com/user-attachments/assets/4e3a6080-a67d-4851-9d10-d8dbf3ceeb04




## 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
- [ ] 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/chatlist/useBulkActions.js

@@ -102,6 +102,28 @@ export function useBulkActions() {
     }
   }
 
+  // Only used in context menu
+  async function onRemoveLabels(labelsToRemove, conversationId = null) {
+    try {
+      await store.dispatch('bulkActions/process', {
+        type: 'Conversation',
+        ids: conversationId || selectedConversations.value,
+        labels: {
+          remove: labelsToRemove,
+        },
+      });
+
+      useAlert(
+        t('CONVERSATION.CARD_CONTEXT_MENU.API.LABEL_REMOVAL.SUCCESFUL', {
+          labelName: labelsToRemove[0],
+          conversationId,
+        })
+      );
+    } catch (err) {
+      useAlert(t('CONVERSATION.CARD_CONTEXT_MENU.API.LABEL_REMOVAL.FAILED'));
+    }
+  }
+
   async function onAssignTeamsForBulk(team) {
     try {
       await store.dispatch('bulkActions/process', {
@@ -189,6 +211,7 @@ export function useBulkActions() {
     isConversationSelected,
     onAssignAgent,
     onAssignLabels,
+    onRemoveLabels,
     onAssignTeamsForBulk,
     onUpdateConversations,
   };