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).

server/routes/lanes.js

@@ -777,6 +777,10 @@ async function cloneInto(req, res, body, before) {
     res.status(400).json({ error: { code: "EBADTOOL", message: "unknown tool" } });
     return null;
   }
+  if (body.partial !== undefined && typeof body.partial !== "boolean") {
+    res.status(400).json({ error: { code: "EBADFIELD", message: "partial: boolean" } });
+    return null;
+  }
   const once = body.credentials;
   if (once != null && (typeof once !== "object" || Array.isArray(once))) {
     res.status(400).json({ error: { code: "EBADCRED", message: "credentials: object" } });
@@ -813,17 +817,32 @@ async function cloneInto(req, res, body, before) {
     return null;
   }
   const ownerId = scope.ownerFor(req);
+  // The browser's own name for this clone, so it can poll its progress.
+  const queue = require("../lib/clone-queue");
+  let job = null;
+  if (body.progressToken !== undefined) {
+    try {
+      job = queue.track(body.progressToken, ownerId);
+    } catch (err) {
+      res.status(400).json({ error: { code: err.code, message: err.message } });
+      return null;
+    }
+  }
   try {
     await before(target, ownerId);
     await identity.cloneRepo({
+      job,
       url,
       parent: dir,
       name,
       once: once
         ? { username: once.username, password: once.password, remember: once.remember === true }
         : null,
+      partial: body.partial === true,
     });
+    queue.finish(job, true);
   } catch (err) {
+    queue.finish(job, false);
     const status = ["EBADCRED", "EBADHOST", "EBADTOOL", "EDISABLED"].includes(err.code)
       ? 400
       : ["ECREDENTIALS", "ESSHAUTH", "ENOREPO", "EOWNERFOLDER", "EMEMBERGONE"].includes(err.code)
@@ -843,6 +862,19 @@ async function cloneInto(req, res, body, before) {
   return { target, name, ownerId };
 }
 
+/**
+ * A clone's place in the machine-wide queue, then git's own progress
+ * (`server/lib/clone-queue.js`), by the `progressToken` its POST carried —
+ * only to the user who started it (404 otherwise, and once it is long over).
+ */
+router.get("/clone/progress/:token", (req, res) => {
+  const view = require("../lib/clone-queue").progress(req.params.token, scope.ownerFor(req));
+  if (!view) {
+    return res.status(404).json({ error: { code: "ENOTFOUND", message: "no such clone" } });
+  }
+  res.json(view);
+});
+
 router.post("/clone", sameOriginGuard, async (req, res) => {
   const body = req.body || {};
   // Before the clone: a workspace this user may not own there, or a tool