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/dashboard/helper/editorHelper.js

@@ -379,31 +379,6 @@ export const findNodeToInsertImage = (editorState, fileUrl) => {
   };
 };
 
-/**
- * Set URL with query and size.
- *
- * @param {Object} selectedImageNode - The current selected node.
- * @param {Object} size - The size to set.
- * @param {Object} editorView - The editor view.
- */
-export function setURLWithQueryAndSize(selectedImageNode, size, editorView) {
-  if (selectedImageNode) {
-    // Create and apply the transaction
-    const tr = editorView.state.tr.setNodeMarkup(
-      editorView.state.selection.from,
-      null,
-      {
-        src: selectedImageNode.src,
-        height: size.height,
-      }
-    );
-
-    if (tr.docChanged) {
-      editorView.dispatch(tr);
-    }
-  }
-}
-
 /**
  * Strips unsupported markdown formatting from content based on the editor schema.
  * This ensures canned responses with rich formatting can be inserted into channels