7-task plan covering schema migration, config knobs, DB + TDLib helpers,
and wiring the skip guards + getChat/getForumTopic short-circuits into
both the forum and non-forum branches of runWorkerForAccount.
Each task ends with a type-check step before its commit so the tree
compiles after every step. Task 7 is manual verification covering
restart safety, failure-retry preservation, and backoff behavior.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
