GHSA-4pjg-x8qj-33j5 - SiYuan: authFilePublishAccess distinguishes hidden and forbidden documents from public and nonexistent ones, and issues a publish-auth cookie for documents it reports as forbidden

### Summary `/api/filetree/authFilePublishAccess` is registered with `CheckAuth` only and is reachable anonymously. It never sets a failure code, so its outcome is signalled entirely by the response message and by whether a `Set-Cookie` header is present. Those two signals differ across access tiers, which lets an anonymous caller determine, for any candidate document identifier, whether that document is public or nonexistent, password-protected, or exists at the hidden or forbidden tier. Separately, hidden and forbidden entries carry an empty password. Submitting `password:""` therefore satisfies the equality check for them, and the server responds by issuing `Set-Cookie: publish-auth-<docID>` for a document whose own tier is forbidden. ### Details **Route,** identical on both refs: ```go ginServer.Handle("POST", "/api/filetree/authFilePublishAccess", model.CheckAuth, authFilePublishAccess) ``` No `CheckAdminRole`, no `CheckReadonly`. **Handler,** `kernel/api/filetree.go:1608` on the development branch and `:1421` on master. `ret.Code` is never assigned on the failure path, so every response carries `code:0`. The branch is: ```go if item.Password == password { // SetPublishAuthCookie } else { ret.Msg = Conf.Language(285) } ``` **The cookie is issued for forbidden documents.** Entries at the hidden and forbidden tiers store `Password == ""`. A request with `password:""` therefore makes `item.Password == password` true for them, and the handler takes the success branch. The server issues a publish-auth cookie for a document it otherwise treats as inaccessible. The cookie itself confers nothing, because those tiers are decided before any password check elsewhere in the codebase. The defect is that the endpoint's success signal does not correspond to access being granted, and that signal is observable. **Three distinguishable outcomes.** With `password:""`, one request per candidate identifier: | Tier of the target | `Set-Cookie` | Body | |---|---|-