feat: Use new compose conversation in conversation sidebar (#11085)

# Pull Request Template

## Description

This PR includes the implementation of the new Compose Conversation form
in the conversation sidebar, replacing the old one.

## Type of change

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

## How Has This Been Tested?

### Loom video

https://www.loom.com/share/4312e20a63714eb892d7b5cd0dcda893?sid=9bd5254e-2b1f-462c-b2c1-a3048a111683

## 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

app/javascript/dashboard/components-next/NewConversation/components/ActionButtons.vue

@@ -232,4 +232,20 @@ useKeyboardEvents(keyboardEvents);
 .emoji-dialog::before {
   @apply hidden;
 }
+
+// The <label> tag inside the file-upload component overlaps the button due to its position.
+// This causes the button's hover state to not work, as it's positioned below the label (z-index).
+// Increasing the button's z-index would break the file upload functionality.
+// This style ensures the label remains clickable while preserving the button's hover effect.
+:deep() {
+  .file-uploads.file-uploads-html5 {
+    label {
+      @apply hover:cursor-pointer;
+    }
+
+    &:hover button {
+      @apply dark:bg-n-solid-2 bg-n-alpha-2;
+    }
+  }
+}
 </style>