chore: Replace plain editor with advanced editor (#13071)

# Pull Request Template

## Description

This PR reverts the plain text editor back to the **advanced editor**,
which was previously removed in
[https://github.com/chatwoot/chatwoot/pull/13058](https://github.com/chatwoot/chatwoot/pull/13058).
All channels now use the **ProseMirror editor**, with formatting applied
based on each channel’s configuration.

This PR also fixes issues where **new lines were not properly preserved
during Markdown serialization**, for both:

* `Enter or CMD/Ctrl+enter` (new paragraph)
* `Shift+Enter` (`hard_break`)

Additionally, it resolves related **[Sentry
issue](https://chatwoot-p3.sentry.io/issues/?environment=production&project=4507182691975168&query=is%3Aunresolved%20markdown&referrer=issue-list&statsPeriod=7d)**.

With these changes:

* Line breaks and spacing are now preserved correctly when saving canned
responses.
* When editing a canned response, the content retains the exact spacing
and formatting as saved in editor.
* Canned responses are now correctly converted to plain text where
required and displayed consistently in the canned response list.

### https://github.com/chatwoot/prosemirror-schema/pull/38

---

## Type of change

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

## How Has This Been Tested?



## 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
- [x] 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: Muhsin Keloth <muhsinkeramam@gmail.com>

pnpm-lock.yaml

@@ -20,8 +20,8 @@ importers:
         specifier: 1.2.3
         version: 1.2.3
       '@chatwoot/prosemirror-schema':
-        specifier: 1.2.6
-        version: 1.2.6
+        specifier: 1.3.4
+        version: 1.3.4
       '@chatwoot/utils':
         specifier: ^0.0.51
         version: 0.0.51
@@ -430,8 +430,8 @@ packages:
   '@chatwoot/ninja-keys@1.2.3':
     resolution: {integrity: sha512-xM8d9P5ikDMZm2WbaCTk/TW5HFauylrU3cJ75fq5je6ixKwyhl/0kZbVN/vbbZN4+AUX/OaSIn6IJbtCgIF67g==}
 
-  '@chatwoot/prosemirror-schema@1.2.6':
-    resolution: {integrity: sha512-ej60kU3m/tP0VoGkOJhj0X+Mxt7fEX5DSEE4IibCZnTM4kMewkMxSYyPu0AXqaA4nKX1hTMrwcbv1t7gVQttWQ==}
+  '@chatwoot/prosemirror-schema@1.3.4':
+    resolution: {integrity: sha512-XY1UyG9topVy7fNCt45YgiU/QzlJJRhrcrSWcvAIIcDYKomnEcGOyeAfM3WeFD6GgOuLzRUyIHrW+WQGpHaZvA==}
 
   '@chatwoot/utils@0.0.51':
     resolution: {integrity: sha512-WlEmWfOTzR7YZRUWzn5Wpm15/BRudpwqoNckph8TohyDbiim1CP4UZGa+qjajxTbNGLLhtKlm0Xl+X16+5Wceg==}
@@ -4909,7 +4909,7 @@ snapshots:
       hotkeys-js: 3.8.7
       lit: 2.2.6
 
-  '@chatwoot/prosemirror-schema@1.2.6':
+  '@chatwoot/prosemirror-schema@1.3.4':
     dependencies:
       markdown-it-sup: 2.0.0
       prosemirror-commands: 1.6.0