chore: v2.8.12 — clone queue and progress, session defaults, chat agents, drops as @ mentions

Whole tree from parallel sessions, plus the version bump:
- Clone: a queue with live progress (Add workspace and extra folders),
  clones run under nice/ionice so the machine stays responsive.
- Settings → AI tools → Session defaults: a new session's default
  permission mode / bypass per account.
- Chat lists the background subagents that have not reported back yet.
- A file pasted or dropped into a claude pane goes in as an @ mention.
- Changes panel: say why amend/undo is refused on a pushed commit.
- openapi.yaml regenerated (Artifacts, Host, resumeById).

client/src/components/lanes/SessionReplay.tsx

@@ -94,7 +94,7 @@ export function SessionReplay({
   const tool = session?.tool || "claude";
   const resumable = byId(tool)?.resumeById ?? RESUMABLE.has(tool);
   const livePane = liveRunFor(lane, liveRuns, sessionId);
-  const text = promptWithImages(prompt, images);
+  const text = promptWithImages(prompt, images, tool === "claude");
 
   const send = async () => {
     if (!text || busy || uploading || livePane || !resumable) return;