feat: Enable users to paste images directly into the chat input using Ctrl + V

[Pratheek555]

As an EmbeddedChat developer

I need to: enable users the ability to easily press ,CTRL + V , and the image they want to upload is ready to go.

So That: Users can quickly upload images without having to click the upload button or drag files between windows.

Acceptance Criteria

• [ ] When the message input is focused and the user presses Ctrl + V, any image present in the clipboard is detected.
• [ ] Normal text pasting behavior remains unchanged when the clipboard contains text only.
• [ ] Non-image clipboard content (e.g., PDFs or unsupported files) does not trigger the image upload flow.