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/AddLaneModal.tsx

@@ -9,7 +9,8 @@
  * manually-typed branch name; "Clone" runs `POST /api/lanes/clone` (an
  * https/ssh URL cloned into a folder of the user's, with their OWN SSH key or
  * HTTPS login — a 409 `ECREDENTIALS` opens a login row, `ESSHAUTH` points to
- * Settings → Git). There is no AI tool picker: the lane is created with the
+ * Settings → Git; **Partial clone** makes it blobless, and `CloneProgress`
+ * shows its queue place, then git's progress). There is no AI tool picker: the lane is created with the
  * default AI tool (Settings → AI Tools), and each new session picks its own
  * AI on the workspace home. Either
  * mode's path field can be filled by typing, by the CwdAutocomplete
@@ -30,6 +31,7 @@ import { useDialog } from "../../hooks/useDialog";
 import { CwdAutocomplete } from "../run/RunSetup";
 import { PathPickButton } from "../PathPickButton";
 import { api } from "../../lib/api";
+import { CloneProgress, newCloneToken } from "./CloneProgress";
 import type { CwdSuggestion } from "../../lib/api";
 import type { Lane, LaneWorktree } from "../../lib/types";
 import { useAiTools } from "../../hooks/useAiTools";
@@ -116,6 +118,9 @@ export function AddLaneModal({
   // server asked for one — a login for the URL's https host.
   const [cloneUrl, setCloneUrl] = useState("");
   const [cloneName, setCloneName] = useState("");
+  const [clonePartial, setClonePartial] = useState(false);
+  /** The running clone's progress token (CloneProgress polls it). */
+  const [cloneToken, setCloneToken] = useState<string | null>(null);
   const [login, setLogin] = useState<{
     host: string;
     username: string;
@@ -159,6 +164,7 @@ export function AddLaneModal({
     setMode("repo");
     setCloneUrl("");
     setCloneName("");
+    setClonePartial(false);
     setLogin(null);
     setSshRefused(false);
     setSourceRepo("");
@@ -236,13 +242,17 @@ export function AddLaneModal({
       const url = cloneUrl.trim();
       if (!url) return;
       setSshRefused(false);
+      const progressToken = newCloneToken();
+      setCloneToken(progressToken);
       try {
         const result = await api.lanes.clone({
+          progressToken,
           url,
           parent: repo,
           name: cloneName.trim() || undefined,
           title: name || undefined,
           tool,
+          ...(clonePartial ? { partial: true } : {}),
           ...(login?.username.trim() && login.token
             ? {
                 credentials: {
@@ -274,6 +284,8 @@ export function AddLaneModal({
           setError(err instanceof Error ? err.message : String(err));
         }
         setBusy(false);
+      } finally {
+        setCloneToken(null);
       }
       return;
     }
@@ -547,6 +559,23 @@ export function AddLaneModal({
                 spellCheck={false}
                 className="w-full rounded-md border border-border-light bg-surface-0 px-3 py-1.5 font-mono text-xs text-fg-primary placeholder:text-fg-muted focus:border-accent focus:outline-none"
               />
+              <label
+                className="mt-2 flex items-center gap-1.5 text-[11px] text-fg-secondary"
+                title={t("clone.partialHint")}
+              >
+                <input
+                  type="checkbox"
+                  data-testid="add-lane-clone-partial"
+                  checked={clonePartial}
+                  onChange={(e) => setClonePartial(e.target.checked)}
+                />
+                {t("clone.partial")}
+              </label>
+              {cloneToken && (
+                <div className="mt-2">
+                  <CloneProgress token={cloneToken} />
+                </div>
+              )}
             </div>
           )}