fix: probe bounded before a realpath in clone and New folder (release review, #516)

Clone ran an unbounded realpath over every Docker case workspace, and the mkdir
route inherited the picker resolver's realpathSync, which freezes the whole server
on a mount that stopped answering. The picker's browse route has the same call and
is left as it was.

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

src/web/routes/case-routes.ts

@@ -802,8 +802,14 @@ export function registerCaseRoutes(
       // with the workspace bind-mounted can write both while it fetches. Like git status, fetch and worktrees,
       // never clone at or inside a Docker case workspace. Fails closed when the Docker case list cannot be read.
       try {
+        // Probed first (#516): a case's workspace can sit on a mount that stopped answering, and an unbounded
+        // realpath there would hold this request and a threadpool worker. Such a root is judged as spelled.
         const roots = await Promise.all(
-          (await defaultDockerWorkspaces()).map((root) => fs.realpath(root).catch(() => resolve(root)))
+          (await defaultDockerWorkspaces()).map(async (root) =>
+            (await probePathKind(root, { pastCap: true })) === 'unknown'
+              ? resolve(root)
+              : fs.realpath(root).catch(() => resolve(root))
+          )
         );
         // A custom folder is already symlink-resolved; the default one is judged through its real cases dir.
         const dest =

src/web/routes/file-routes.ts

@@ -1457,6 +1457,15 @@ export function registerFileRoutes(app: FastifyInstance, ctx: SessionPort & Even
   // "New folder" in the path picker: creates ONE folder directly inside a folder the picker may browse.
   app.post('/api/filesystem/mkdir', async (req, reply): Promise<ApiResponse<{ path: string }>> => {
     const { path: parentPath, name, sessionId, showHidden } = parseBody(FilesystemMkdirSchema, req.body);
+    // Probed first (#516): the picker's resolver runs realpathSync on this path, which would freeze the
+    // whole server on a mount that stopped answering.
+    if ((await probePathKind(parentPath, { pastCap: true })) === 'unknown') {
+      reply.code(422);
+      return createErrorResponse(
+        ApiErrorCode.OPERATION_FAILED,
+        describeUnknownPath('The folder', parentPath, { pastCap: true })
+      );
+    }
     const { candidatePath, resolvedPath, blockedTrees } = await resolveFilesystemPickerPath(
       ctx,
       req,