Legacy kanban boards (pre-AUTOINCREMENT schema) crashed the gateway
notifier on every tick — int(None) on a NULL id in unseen_events_for_sub
— silently losing all kanban notifications. CREATE TABLE IF NOT EXISTS
skips existing tables regardless of schema and _add_column_if_missing
only adds columns, so neither could fix a drifted primary-key type.
_rebuild_drifted_tables() detects the legacy shape via PRAGMA table_info
and rebuilds task_events/task_comments/task_runs (TEXT PK -> INTEGER
AUTOINCREMENT) and kanban_notify_subs.last_event_id (TEXT/NULL -> INTEGER
NOT NULL DEFAULT 0), preserving data. The whole pass is one transaction
so an interruption can't leave a table half-renamed, and recreates every
index DROP TABLE would otherwise take down (including idx_events_run).
Co-authored-by: liuhao1024 <liuhao1024@users.noreply.github.com>
