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/run/PaneGrid.tsx

@@ -244,9 +244,9 @@ const ITEM =
  *  the draft (its files as paths) back into the input box, never sent. */
 /** A session's chat switched to its terminal: the unsent prompt goes into
  *  the CLI's input box, without Enter. */
-export function showTerminal(runId: string, sessionId: string) {
+export function showTerminal(runId: string, sessionId: string, tool?: string) {
   const draft = readChatDraft(sessionId);
-  const { text, files } = promptForPane(draft.prompt, draft.images);
+  const { text, files } = promptForPane(draft.prompt, draft.images, tool === "claude");
   if ((text || files.length) && pasteToRun(runId, text, files)) writeChatDraft(sessionId, "", []);
   setSessionChat(sessionId, false);
 }
@@ -265,7 +265,7 @@ function ChatToggle({ run }: { run?: RunHandle }) {
       title={label}
       aria-label={label}
       onClick={() => {
-        if (chat) return showTerminal(run.id, sessionId);
+        if (chat) return showTerminal(run.id, sessionId, run.tool);
         const draft = readChatDraft(sessionId);
         const text = takeRunInput(run.id);
         if (text)