Chat: insert uploaded image paths at the paste or pick position #3216

Reproduction

1. Type before after in the Chat message box.
2. Put the caret before after and paste an image, or pick a file.
3. Keep typing or move the caret while the upload finishes.

The uploaded path appears at the beginning of the draft. Expected: insert it where the paste or pick occurred, adjusted for edits made while uploading. Keep the current focus and selection, and leave selected prose intact rather than deleting it when the upload finishes.

Files picked together should keep their order. IME composition, slash commands, failed uploads and retries should retain their existing safeguards. An upload started in a cleared or replaced draft must not insert into the new draft.

Closed #120 addresses whitespace around image paths. #2771 addresses upload-path validation, and #801 covers Android screenshot paste. I did not find an issue for placement at the original caret.

Would you accept this change? It would keep the current @path format and attachment controls. No new setting or rich-text editor.