Reviewer follow-up to PR #2134 (Optional finding). The history loader
walked text on the user branch but never extracted file parts — so a
chat reload after a session where the user dragged in a file rendered
the text bubble but lost the download chip. Symmetric to the agent
branch which already handles this via extractFilesFromTask.
Wire shape from ChatTab's outbound POST:
request_body = {params: {message: {parts: [
{kind: "text", text: "..."},
{kind: "file", file: {uri, name, mimeType?, size?}}
]}}}
extractFilesFromTask walks `task.parts`, so we feed it `params.message`
(the inner object that has the parts array). Three new tests:
- hydrates file attachments from request_body
- emits an attachments-only bubble when text is empty (drag-drop
without caption — pre-fix the empty userText short-circuited and
the row was dropped entirely)
- internal-self predicate suppresses the row even with attachments
(defence-in-depth for future internal triggers)
Stacked on #2134; this branch's parent commit is its tip.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
6430b3b699