fix: Variable search item not showing after braces/commas (#11864)

# Pull Request Template

## Description

This PR fixes an issue where typing variables, like `{{contact.name}}`,
caused the variable list to miss showing `contact.name`. The search key
in this case became `contact.name}},` which didn't match any available
options. The logic in `VariableList.vue` only checked the part after the
last comma and didn’t fully sanitize the input.

**Solution**
Updated `searchKey` to remove all {} and commas for accurate matching.

Fixes
[CW-4574](https://linear.app/chatwoot/issue/CW-4574/i-dont-see-an-option-for-contactname-it-shows-initially-but-it-doesnt)

## Type of change

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

## How Has This Been Tested?

### Loom video

https://www.loom.com/share/fc86e53853ad49e6acf6de57ebbd8fcb?sid=6702f896-d1a3-4c5a-9eb7-b96b5ed91531


## 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/helper/specs/commons.spec.js

@@ -4,6 +4,7 @@ import {
   convertToAttributeSlug,
   convertToCategorySlug,
   convertToPortalSlug,
+  sanitizeVariableSearchKey,
 } from '../commons';
 
 describe('#getTypingUsersText', () => {
@@ -107,3 +108,37 @@ describe('convertToPortalSlug', () => {
     expect(convertToPortalSlug('Room rental')).toBe('room-rental');
   });
 });
+
+describe('sanitizeVariableSearchKey', () => {
+  it('removes braces', () => {
+    expect(sanitizeVariableSearchKey('{{contact.name}}')).toBe('contact.name');
+  });
+
+  it('removes right braces', () => {
+    expect(sanitizeVariableSearchKey('contact.name}}')).toBe('contact.name');
+  });
+
+  it('removes braces, comma and whitespace', () => {
+    expect(sanitizeVariableSearchKey(' {{contact.name }},')).toBe(
+      'contact.name'
+    );
+  });
+
+  it('trims whitespace', () => {
+    expect(sanitizeVariableSearchKey('  contact.name  ')).toBe('contact.name');
+  });
+
+  it('handles multiple commas', () => {
+    expect(sanitizeVariableSearchKey('{{contact.name}},,')).toBe(
+      'contact.name'
+    );
+  });
+
+  it('returns empty string when only braces/commas/whitespace', () => {
+    expect(sanitizeVariableSearchKey(' {  }, , ')).toBe('');
+  });
+
+  it('returns empty string for undefined input', () => {
+    expect(sanitizeVariableSearchKey()).toBe('');
+  });
+});