fix(auth): восстанавливать раздел и фильтры после входа Portal

lib/auth.ts

@@ -1,4 +1,5 @@
 /** Portal JWT storage + claims helpers for MikrotikManager. */
+import { safeAuthReturnPath } from "./auth-return-path"
 
 const TOKEN_KEY = "mmapp_token"
 const HANDOFF_KEY = "mmapp_auth_401_handoff"
@@ -125,9 +126,12 @@ export function redirectToPortalLogin(returnTo?: string): boolean {
     return false
   }
   markPortalHandoff()
-  const callback = returnTo ?? `${window.location.origin}/auth/callback`
+  const callback = new URL(returnTo ?? `${window.location.origin}/auth/callback`)
+  const next = safeAuthReturnPath(callback.searchParams.get("next")) ??
+    safeAuthReturnPath(window.location.pathname + window.location.search)
+  if (next) callback.searchParams.set("next", next)
   const url = new URL(authPortalUrl())
-  url.searchParams.set("return_to", callback)
+  url.searchParams.set("return_to", callback.toString())
   window.location.assign(url.toString())
   return true
 }