chore: support PFX filetype in attachment uploads (#14456)

# Pull Request Template

## Description

This PR expands the default upload rules to support PFX certificate
files (`application/x-pkcs12`, `application/pkcs12`, `.pfx`) across
private notes, Website, Email, and Telegram channels.

Also adds `.xls` / `.xlsx` extension fallbacks for cases where browsers
upload Excel files with an empty or generic MIME type.

### Utils Repo PR: https://github.com/chatwoot/utils/pull/61

Fixes
https://linear.app/chatwoot/issue/CW-7085/support-more-file-types-in-private-notes-and-in-app

## Type of change

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

## How Has This Been Tested?

### Screenshots
<img width="330" height="218" alt="image"
src="https://github.com/user-attachments/assets/80823250-893e-4509-adb9-61f845359151"
/>



## 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

---------

Co-authored-by: aakashb95 <aakashbakhle@gmail.com>

app/javascript/dashboard/components-next/icon/FileIcon.vue

@@ -18,6 +18,7 @@ const fileTypeIcon = computed(() => {
     json: 'i-woot-file-txt',
     odt: 'i-woot-file-doc',
     pdf: 'i-woot-file-pdf',
+    pfx: 'i-woot-file-pfx',
     ppt: 'i-woot-file-ppt',
     pptx: 'i-woot-file-ppt',
     rar: 'i-woot-file-zip',

app/javascript/dashboard/components/widgets/WootWriter/ReplyBottomPanel.vue

@@ -7,7 +7,6 @@ import * as ActiveStorage from 'activestorage';
 import inboxMixin from 'shared/mixins/inboxMixin';
 import { FEATURE_FLAGS } from 'dashboard/featureFlags';
 import { getAllowedFileTypesByChannel } from '@chatwoot/utils';
-import { ALLOWED_FILE_TYPES } from 'shared/constants/messages';
 import VideoCallButton from '../VideoCallButton.vue';
 import { INBOX_TYPES } from 'dashboard/helper/inbox';
 import { mapGetters } from 'vuex';
@@ -166,11 +165,6 @@ export default {
       uploadRef,
     };
   },
-  data() {
-    return {
-      ALLOWED_FILE_TYPES,
-    };
-  },
   computed: {
     ...mapGetters({
       accountId: 'getCurrentAccountId',
@@ -212,13 +206,11 @@ export default {
       return this.conversationType === 'instagram_direct_message';
     },
     allowedFileTypes() {
-      // Use default file types for private notes
       if (this.isOnPrivateNote) {
-        return this.ALLOWED_FILE_TYPES;
+        return getAllowedFileTypesByChannel();
       }
 
       let channelType = this.channelType || this.inbox?.channel_type;
-
       if (this.isAnInstagramChannel || this.isInstagramDM) {
         channelType = INBOX_TYPES.INSTAGRAM;
       }

app/javascript/shared/helpers/FileHelper.js

@@ -1,6 +1,5 @@
 import { getAllowedFileTypesByChannel } from '@chatwoot/utils';
 import { INBOX_TYPES } from 'dashboard/helper/inbox';
-import { ALLOWED_FILE_TYPES } from 'shared/constants/messages';
 
 export const DEFAULT_MAXIMUM_FILE_UPLOAD_SIZE = 40;
 
@@ -58,9 +57,8 @@ export const isFileTypeAllowedForChannel = (file, options = {}) => {
     isOnPrivateNote,
   } = options;
 
-  // Use broader file types for private notes (matches file picker behavior)
   const allowedFileTypes = isOnPrivateNote
-    ? ALLOWED_FILE_TYPES
+    ? getAllowedFileTypesByChannel()
     : getAllowedFileTypesByChannel({
         channelType:
           isInstagramChannel || conversationType === 'instagram_direct_message'