E2E: Fix E2EE room timeline actions (@wip cluster E)

[mjkatgithub]

Planning

• Milestone: Phase 3
• Priority: P0
• Size: M
• Estimate: 3 SP
• Epic: Re-enable @wip chat E2E scenarios quarantined for green CI lane #134

Goal

Fix E2EE seeded test room so composer/thread actions reach the timeline and
persist (upload, edit, pin, reactions, reply scroll).

Scope

• Upload and send audio file
• Thread sidebar open post and persist after reload
• Edit sent message and persist after reload
• Pin message, list, navigate, and unpin
• Add and remove message reaction
• Reply to image shows thumbnail and scrolls to original
• Remove @wip per scenario when green

Branch

bug/e2e-wip-e2ee-timeline

Acceptance criteria

• All six cluster E scenarios pass without @wip.
• Other green E2EE room scenarios unchanged.

Test checklist

E2E

• Cluster E scenarios in chat.feature
• npm run test:ci:full after all @wip removed project-wide

Notes

Shared root cause: actions never reach timeline / sync after reload.
Docs: update docs/architecture.md if timeline module boundaries change.