[Bug]: deepseek --file upload fails silently

[Benjamin-eecs]

Description

opencli deepseek ask --file silently fails with [NO RESPONSE]. Three bugs in utils.js:

1. sendMessage clicked the wrong button. btn.closest('div')?.querySelector('textarea') always returned null (the button IS a div, so closest('div') returns itself). Every send used the Enter key fallback. When the send button was disabled during file upload, it clicked the attachment button instead.

2. sendWithFile sent the message before upload finished. DeepSeek shows the file preview chip immediately (optimistic UI) but the send button stays aria-disabled="true" until the PoW challenge + server upload completes (~2s). The code sent the message as soon as the preview appeared.

3. DataTransfer ownership transfer. inp.files = dt.files transfers the FileList ownership and empties dt.files. The code then passed the now-empty dt.files to React's onChange handler.

Steps to Reproduce

echo "The answer is 42." > /tmp/test.txt
opencli deepseek ask "what number is in this file" --new --file /tmp/test.txt --timeout 60
# Returns: [NO RESPONSE] No reply within 60s.

Expected Behavior

- response: The number in the file is 42.

OpenCLI Version

1.7.7

Node.js Version

Other

Operating System

macOS