Task 12 (the AuthContext userKeyState refactor) replaced the per-device
DeviceRecord lookup with a localStorage UUID via ensureInstallId(). That
UUID was then passed straight through to messages.sender_device_id on
INSERT.
The messages_insert_member RLS policy requires sender_device_id to be
NULL OR to match a row in `devices` owned by the caller. The localStorage
UUID matches neither -> 403 -> outbox endlessly retries with "Wiederhole".
Fix: SendMessageParams.senderDeviceId becomes optional, and the message
INSERT coerces undefined to NULL. The column is pure telemetry post-conv-
keys so passing NULL is correct. Existing call sites that hand in
ensureInstallId() still typecheck (string is assignable to string|null|undefined)
but the row is written with NULL until those callers stop passing it.
byGalax
c9fe4879e0