Query
CREATE TABLE subscription_events (
id INTEGER PRIMARY KEY AUTOINCREMENT,
account_id INTEGER NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,
event TEXT NOT NULL,
-- 'trial_started',
'subscribed',
'seats_changed',
-- 'cancelled',
'read_only_started',
'deleted',
...
data TEXT,
-- optionales JSON
created_at TEXT NOT NULL DEFAULT (datetime('now'))
)