chore: support custom variables in auto-resolution message (#14782)

# Pull Request Template

## Description

This PR adds support for custom variables in auto-resolution messages
within Conversation Workflows.

Agents can insert variables (e.g. `{{contact.name}}`) into the custom
auto-resolution message using the variable picker by typing `{{`. These
variables are resolved with actual conversation data when the
auto-resolution message is sent.

The field uses the existing editor with the formatting toolbar hidden,
since auto-resolution messages are delivered across all channels,
including SMS, where formatting isn't supported. Existing message
content is preserved as-is, and typing `{{` opens the variable picker
for quick insertion.

Fixes
https://linear.app/chatwoot/issue/CW-7369/support-custom-variables-in-conversations-workflow-text-fields

## Type of change

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

## How Has This Been Tested?

### Screenshots
<img width="1262" height="764" alt="image"
src="https://github.com/user-attachments/assets/e43be22c-f86e-436a-9fdd-5bcb73c61ca3"
/>



## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [ ] 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/constants/editor.js

@@ -163,6 +163,11 @@ export const FORMATTING = {
     nodes: [],
     menu: [],
   },
+  'Context::NoToolbar': {
+    marks: ['strong', 'em', 'link'],
+    nodes: ['bulletList', 'orderedList'],
+    menu: [],
+  },
 };
 
 // Editor menu options for Full Editor

app/javascript/dashboard/routes/dashboard/settings/account/components/AutoResolve.vue

@@ -5,7 +5,7 @@ import { useI18n } from 'vue-i18n';
 import { useAccount } from 'dashboard/composables/useAccount';
 import { useAlert } from 'dashboard/composables';
 import WithLabel from 'v3/components/Form/WithLabel.vue';
-import TextArea from 'next/textarea/TextArea.vue';
+import Editor from 'next/Editor/Editor.vue';
 import Switch from 'next/switch/Switch.vue';
 import NextButton from 'dashboard/components-next/button/Button.vue';
 import DurationInput from 'next/input/DurationInput.vue';
@@ -162,9 +162,13 @@ const toggleAutoResolve = async () => {
           :label="t('GENERAL_SETTINGS.FORM.AUTO_RESOLVE.MESSAGE.LABEL')"
           :help-message="t('GENERAL_SETTINGS.FORM.AUTO_RESOLVE.MESSAGE.HELP')"
         >
-          <TextArea
+          <Editor
             v-model="message"
             class="w-full"
+            channel-type="Context::NoToolbar"
+            enable-variables
+            :enable-canned-responses="false"
+            :show-character-count="false"
             :placeholder="
               t('GENERAL_SETTINGS.FORM.AUTO_RESOLVE.MESSAGE.PLACEHOLDER')
             "