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/components/widgets/conversation/contextMenu/Index.vue

@@ -53,6 +53,10 @@ export default {
       type: String,
       default: null,
     },
+    conversationLabels: {
+      type: Array,
+      default: () => [],
+    },
     conversationUrl: {
       type: String,
       default: '',
@@ -70,6 +74,7 @@ export default {
     'assignAgent',
     'assignTeam',
     'assignLabel',
+    'removeLabel',
     'deleteConversation',
     'close',
   ],
@@ -334,8 +339,16 @@ export default {
           v-for="label in labels"
           :key="label.id"
           :option="generateMenuLabelConfig(label, 'label')"
-          variant="label"
-          @click.stop="$emit('assignLabel', label)"
+          :variant="
+            conversationLabels.includes(label.title)
+              ? 'label-assigned'
+              : 'label'
+          "
+          @click.stop="
+            conversationLabels.includes(label.title)
+              ? $emit('removeLabel', label)
+              : $emit('assignLabel', label)
+          "
         />
       </MenuItemWithSubmenu>
       <MenuItemWithSubmenu