[FEATURE] "Uploading" visual clue

### Preflight Checklist

- [x] I have searched [existing requests](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20label%3Aenhancement) and this feature hasn't been requested yet
- [x] This is a single feature request (not multiple features)

### Problem Statement

Claude displays a spinner and some random funny strings when it's actually uploading, not doing what the strings suggest.

### Proposed Solution

Please make it clear that it is actually uploading, as this is very important to know especially when the dev has a slow upload speed.

### Alternative Solutions

_No response_

### Priority

Medium - Would be very helpful

### Feature Category

Interactive mode (TUI)

### Use Case Example

_No response_

### Additional Context

_No response_

Start in the interactive-mode (TUI) code by locating the spinner and random status strings, then trace how the upload phase is represented. Confirm the existing upload flow and identify where its status is rendered. Done means the interface visibly indicates that an upload is in progress instead of showing unrelated activity text.

Written by the indexing model from the issue text.