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/RunSetup.tsx

@@ -67,6 +67,7 @@ import { TOKEN_TONE, promptTokens } from "../../lib/promptTokens";
 import {
   ATTACH_MIME,
   addAttachments,
+  claudeMention,
   droppedAttachments,
   droppedSkill,
   droppedText,
@@ -203,21 +204,29 @@ interface PromptEditorProps {
 export type PromptImage = { path: string; url?: string; name: string };
 
 /** The prompt as sent: the text, then each file's saved path — which is how
- *  the CLI is handed an image or a file. */
-export function promptWithImages(text: string, images: PromptImage[]): string {
-  return [text.trim(), ...images.map((i) => i.path)].filter(Boolean).join(" ");
+ *  the CLI is handed an image or a file; for `claude`, as `@` mentions. */
+export function promptWithImages(text: string, images: PromptImage[], claude = false): string {
+  return [text.trim(), ...images.map((i) => (claude ? claudeMention(i.path) : i.path))]
+    .filter(Boolean)
+    .join(" ");
 }
 
 const IMAGE_PATH = /^[^@].*\.(png|jpe?g|gif|webp)$/i;
 
-/** The prompt as pasted into a live pane: the text with every non-image file
- *  in it (as `promptWithImages`), and the images' paths apart — each goes in
- *  a paste of its own, the one shape `claude` turns into `[Image #n]` on every
- *  platform (a Windows path inside a paste of text stayed a plain path). */
+/** The prompt as pasted into a live pane. `claude`: one paste, every file an
+ *  `@` mention, and a trailing space so a mention at the end does not leave
+ *  the `@` file suggester open to swallow the Enter after it. Any other tool:
+ *  the text with every non-image file in it, and the images' paths apart,
+ *  each in a paste of its own (how `codex` attaches a pasted image path). */
 export function promptForPane(
   text: string,
-  images: PromptImage[]
+  images: PromptImage[],
+  claude = false
 ): { text: string; files: string[] } {
+  if (claude) {
+    const all = promptWithImages(text, images, true);
+    return { text: images.length ? `${all} ` : all, files: [] };
+  }
   const isImage = (i: PromptImage) => IMAGE_PATH.test(i.path);
   return {
     text: promptWithImages(text, images.filter((i) => !isImage(i))),