S00-003: Record blocked task and remediation handoff

Changes: Preserve incomplete work and blocker metadata for S00-003. This checkpoint does not mark implementation accepted.
Validation: Session ended with status blocked.
Blocker: S00-003 cannot attest parser limits: Stanza 12.22.1 exposes no resource bounds and its persistent WebSocket parser accepts large/deep XML and reassembles incomplete documents across separate input messages.

Task: S00-003
Agent: auto-protocol-902594b44429
Role: protocol
Action: claim
Status: blocked

Task title: Проверить XMPP WSS/auth библиотеку

planning/stages/S00.md

@@ -8,7 +8,7 @@
 
 - [S00-001](../tasks/S00-001.md): Утвердить Web-профиль — orchestrator; done.
 - [S00-002](../tasks/S00-002.md): Выбрать framework и build runtime — orchestrator; done.
-- [S00-003](../tasks/S00-003.md): Проверить XMPP WSS/auth библиотеку — protocol; todo.
+- [S00-003](../tasks/S00-003.md): Проверить XMPP WSS/auth библиотеку — protocol; blocked.
 - [S00-004](../tasks/S00-004.md): Проверить browser OMEMO backend — crypto; todo.
 - [S00-005](../tasks/S00-005.md): Выбрать IndexedDB wrapper и migration policy — storage; todo.
 - [S00-006](../tasks/S00-006.md): Зафиксировать browser/reference matrix — orchestrator; todo.
@@ -22,6 +22,7 @@
 - [S00-015](../tasks/S00-015.md): Устранить прерывание: Fix runner prompt delivery after partial stdin timeout — ci-cd; done.
 - [S00-016](../tasks/S00-016.md): Restore reviewer model availability after provider capacity failure — ci-cd; done.
 - [S00-017](../tasks/S00-017.md): Establish fail-closed SCRAM server-final validation — protocol; done.
+- [S00-018](../tasks/S00-018.md): Validate bounded standalone XML ingress for the XMPP candidate — protocol; todo.
 - [S00-010](../tasks/S00-010.md): Gate: Профиль и проверка стека — qa; todo.
 
 ## Граница этапа