S00-020: Record blocked task and remediation handoff

Changes: Preserve incomplete work and blocker metadata for S00-020. This checkpoint does not mark implementation accepted.
Validation: Session ended with status blocked.
Blocker: Previous runner session was interrupted before submit/escalate; processes stopped. User now explicitly requests resuming development. Preserve partial artifacts, verify them in a fresh bounded remediation, and return original to a new executor only after independent review.

Task: S00-020
Agent: auto-ci-cd-5a18c8aa1b42
Role: ci-cd
Action: claim
Status: blocked

Task title: Restore access to the pinned Linux XMPP experiment toolchain

planning/stages/S00.md

@@ -24,10 +24,11 @@
 - [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; done.
 - [S00-019](../tasks/S00-019.md): Validate browser-compatible SCRAM-SHA-512 through a public mechanism API — crypto; done.
-- [S00-020](../tasks/S00-020.md): Restore access to the pinned Linux XMPP experiment toolchain — ci-cd; in_progress.
+- [S00-020](../tasks/S00-020.md): Restore access to the pinned Linux XMPP experiment toolchain — ci-cd; blocked.
 - [S00-021](../tasks/S00-021.md): Устранить прерывание: Проверить browser OMEMO backend — crypto; done.
 - [S00-022](../tasks/S00-022.md): Confirm or source a verified browser/WASM-capable OMEMO2 backend for the Web client endpoint — crypto; blocked.
 - [S00-023](../tasks/S00-023.md): Устранить прерывание: Выбрать IndexedDB wrapper и migration policy — storage; todo.
+- [S00-024](../tasks/S00-024.md): Устранить прерывание: Restore access to the pinned Linux XMPP experiment toolchain — ci-cd; todo.
 - [S00-010](../tasks/S00-010.md): Gate: Профиль и проверка стека — qa; todo.
 
 ## Граница этапа