feat: inline images in website and email channels (#14516)

# Pull Request Template

## Description

This PR adds support for inline image uploads in the reply editor for
Email and Website (chat widget) channels.

Agents can now insert images inline between text and resize them
directly in the editor by dragging the bottom corner, similar to the
help center editor experience.

Image sizes are preserved through markdown using the `cw_image_width`
URL param and render correctly in both outgoing emails and chat widget
messages.

Agents can also paste copied images directly into Email or Website
replies using **Shift+Cmd+V** (Shift+Ctrl+V on Windows/Linux). The image
gets inserted inline at the cursor position and supports resizing just
like uploaded images. Regular **Cmd+V / Ctrl+V** behavior remains
unchanged and continues to add images as attachments, so both inline and
attachment flows are supported.


### Prosemirror repo PR:
https://github.com/chatwoot/prosemirror-schema/pull/48

Fixes
https://linear.app/chatwoot/issue/CW-7133/inline-images-in-live-chat-and-email

https://linear.app/chatwoot/issue/CW-7225/ghsa-8j9w-jppp-xcfc-html-attribute-injection-via-unvalidated-cw-image

## Type of change

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

## How Has This Been Tested?

### Screencast



https://github.com/user-attachments/assets/a928f852-ab15-413a-9d35-6ea69b718ecf

<img width="414" height="654" alt="image"
src="https://github.com/user-attachments/assets/205e0729-8f2d-4cc5-9c55-7696f032eca4"
/>



## 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

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/shared/helpers/MessageFormatter.js

@@ -1,28 +1,37 @@
+import MarkdownIt from 'markdown-it';
 import mila from 'markdown-it-link-attributes';
 import mentionPlugin from './markdownIt/link';
-import MarkdownIt from 'markdown-it';
 
-const setImageHeight = inlineToken => {
+const setImageSizing = inlineToken => {
   const imgSrc = inlineToken.attrGet('src');
   if (!imgSrc) return;
   const url = new URL(imgSrc);
+  const width = url.searchParams.get('cw_image_width');
+  if (width) {
+    inlineToken.attrSet(
+      'style',
+      `width: ${width}; max-width: 100%; height: auto;`
+    );
+    return;
+  }
   const height = url.searchParams.get('cw_image_height');
-  if (!height) return;
-  inlineToken.attrSet('style', `height: ${height};`);
+  if (height) inlineToken.attrSet('style', `height: ${height};`);
 };
 
 const processInlineToken = blockToken => {
   blockToken.children.forEach(inlineToken => {
     if (inlineToken.type === 'image') {
-      setImageHeight(inlineToken);
+      setImageSizing(inlineToken);
     }
   });
 };
 
 const imgResizeManager = md => {
-  // Custom rule for image resize in markdown
-  // If the image url has a query param cw_image_height, then add a style attribute to the image
-  md.core.ruler.after('inline', 'add-image-height', state => {
+  // If the image URL carries a cw_image_width or cw_image_height query param,
+  // add an inline style attribute so the rendered <img> respects the agent's
+  // resize choice. Width takes precedence (HC drag-resize); height is kept for
+  // legacy messages and the message-signature use case.
+  md.core.ruler.after('inline', 'add-image-sizing', state => {
     state.tokens.forEach(blockToken => {
       if (blockToken.type === 'inline') {
         processInlineToken(blockToken);