attemptCount tracks how many times the worker has tried each failed
source message. Combined with WORKER_MAX_SKIP_ATTEMPTS (default 5), the
worker will auto-retry across cycles but eventually let the watermark
advance past a chronically failing file so cycles aren't pinned forever.
The SkippedPackage row stays so the user can manually retry via the UI.
CHANNEL_ACCESS_LOST is a new notification type the worker emits when a
source channel becomes inaccessible (account got removed, channel
deleted, etc.) — surfaces the issue instead of silently failing every
cycle as we've been doing with "Iridium 2 w/ Add-ons [Completed]".
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
