Feature: Delete own messages (redact)

[mjkatgithub]

Planning

• Milestone: Phase 3
• Priority: P2
• Size: S
• Estimate: 2 SP

Goal

Allow users to delete their own messages via Matrix redaction (m.room.redaction), with correct timeline rendering and permissions.

Scope

• Delete action on own messages (message action bar or context menu).
• Call Matrix redact API (extend existing redactEvent in useMatrixClient if needed).
• Respect power levels (own messages always; others only if PL allows — out of scope for v1 unless trivial).
• Timeline shows deleted placeholder (existing chatTimeline redacted handling).
• Works in main timeline and thread view.
• i18n EN/DE for confirm + success/error.

Branch

feature/message-delete

Acceptance Criteria

• User can delete an own text message from the chat UI.
• Deleted message renders as deleted placeholder, not removed abruptly.
• Delete is reflected for other clients via sync.
• Cannot delete others' messages without permission (hide or disable action).
• Error feedback when redact fails (network/permission).

Test Checklist

Unit

• Permission helper for delete-own vs redact-others (if extracted).
• Timeline mapping still marks redacted events correctly.

Manuell / E2E

• Delete own message in channel; placeholder visible.
• Second client/session sees redaction.
• Delete in thread updates thread view.

Notes

• useMatrixClient.redactEvent exists for reactions; reuse pattern for messages.
• Element reference: message context menu → Remove / Delete.

Epic

Sub-issue of #3 (Phase 3).