feat: v2.7.7 — File Explorer on workspaces and the user's home, clone with per-user git identity

- File Explorer (Files in the sidebar, /files; also from a workspace's Files
  tab, portalled so no panel clips it), laid out like GNOME Files: places
  (Home, workspaces, Trash), Back/Forward/Up, path bar, search, icon grid with
  image thumbnails or list, labelled New/Upload, selection action bar, hidden
  files behind Ctrl+H, right-click menus and the usual keys.
  Make, rename, move, copy (within a workspace, between workspaces, home ↔
  workspace), delete into a per-account trash restorable for 7 days, streamed
  upload of files and whole folders (≤ 500 MB a batch, Replace / Keep both /
  Skip on a taken name), download a file or a zip of anything.
  server/lib/file-explorer.js, /api/lanes/:id/fs/*, /api/homes/:who/fs/*.
- The user's home: every dot entry at its top stays hidden and refused
  (also via a symlink, download, zip or as a copy source); an admin may view
  other users' homes read-only, audited.
- write-as learns move/copy (re-run `sudo agenthub server install-system`).
- Hardening: a write to a workspace re-checks its owner by the live role;
  S3 keeps its server.conf if the file stops reading and a tmux call never
  falls back to the host's server; the AI Proxy gateway marks what it relays
  and the dashboard refuses it; a NUL in a pane's argv/env is refused.
- OpenAPI for the new routes (server/openapi-extra/files.js); docs (API,
  SERVER-MODE, CLAUDE.md) updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

client/src/components/lanes/LaneChangesPanel.tsx

@@ -102,7 +102,7 @@ import {
   Sparkles,
   Trash2,
   UnfoldVertical,
-  Upload,
+  FolderOpen,
 } from "lucide-react";
 import { api, gitTarget } from "../../lib/api";
 import { pasteToLane } from "../../lib/panePaste";
@@ -123,6 +123,7 @@ import {
   type LaneDiffChange,
 } from "./LaneDiffView";
 import { LaneConflictView } from "./LaneConflictView";
+import { FileExplorer } from "./FileExplorer";
 import { ContextMenu, MenuItem, MenuSeparator, useContextMenu } from "../ContextMenu";
 import { MarkdownPreview, isMarkdown } from "../MarkdownPreview";
 import { LaneGitHeader, useLaneGitFacts } from "./LaneGitHeader";
@@ -1639,6 +1640,14 @@ export function LaneChangesPanel({
               {t("changes.uploadHere")}
             </MenuItem>
           )}
+          {treeCtx.menu.item.dir && (
+            <MenuItem
+              testId="lane-changes-menu-explorer"
+              onSelect={pick(treeCtx.close, () => setExplorer({ path: treeCtx.menu!.item.path }))}
+            >
+              {t("changes.openInExplorer")}
+            </MenuItem>
+          )}
           <MenuItem onSelect={pick(treeCtx.close, () => copy(treeCtx.menu!.item.path))}>
             {t("changes.copyPath")}
           </MenuItem>
@@ -1888,7 +1897,11 @@ export function LaneChangesPanel({
   // upload only creates, into the folder it was asked for ("" = the root).
   const uploadInput = useRef<HTMLInputElement>(null);
   const uploadDir = useRef("");
-  const [uploading, setUploading] = useState(false);
+  const [, setUploading] = useState(false);
+  // The File Explorer (the toolbar button where Upload was); the tree is
+  // re-read when it closes after changing anything.
+  const [explorer, setExplorer] = useState<{ path: string } | null>(null);
+  const explorerChanged = useRef(false);
   const download = (path: string) => {
     const a = document.createElement("a");
     a.href = api.lanes.gitDownloadUrl(target, path);
@@ -2121,9 +2134,24 @@ export function LaneChangesPanel({
           aria-label={t("changes.quickOpen")}
           className="w-full rounded border border-border bg-surface-1 px-2 py-1 font-mono text-[11px] text-fg-primary"
         />
-        <IconButton label={t("changes.upload")} disabled={uploading} onClick={() => pickUpload("")}>
-          <Upload className="h-3.5 w-3.5" />
+        <IconButton label={t("changes.openExplorer")} onClick={() => setExplorer({ path: "" })}>
+          <FolderOpen className="h-3.5 w-3.5" />
         </IconButton>
+        <FileExplorer
+          open={!!explorer}
+          laneId={laneId}
+          session={session}
+          source={source}
+          initialPath={explorer?.path ?? ""}
+          onChanged={() => (explorerChanged.current = true)}
+          onClose={() => {
+            setExplorer(null);
+            if (explorerChanged.current) {
+              explorerChanged.current = false;
+              void rereadAll();
+            }
+          }}
+        />
         <input
           ref={uploadInput}
           type="file"