fix(computers): delete large agent files without downloading

Hash remote files through confined descriptors in bounded chunks before editor mutations. Preserve the remote compare-and-swap removal check and read-size cap; cover a real 17 MiB file, stale deletion, and path confinement.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

server/src/modules/computers/application/service.ts

@@ -702,6 +702,9 @@ finally:
       async stat(path: string): Promise<{ name: string; kind: "file" | "directory"; size: number; mtimeMs: number }> {
         return remote({ action: "stat", path });
       },
+      async hash(path: string): Promise<{ sha256: string; size: number }> {
+        return remote({ action: "hash", path });
+      },
       async remove(path: string, expectedSha256: string) {
         await remote({ action: "remove", path, expectedSha256 });
       },