Closes #64.
Migration 0028 inserted gitbay-bot unconditionally. The name was not
reserved before that migration, so an instance upgrading from v1.0.x may
already have a user holding it — the insert hits the UNIQUE constraint on
users.username, the migration aborts, and the daemon does not start. An
org of the same name is the quieter version: the insert succeeds and the
instance ends up with a user and an org sharing one owner name.
Editing 0028 rather than adding 0029, because 0028 is unreleased (v1.0.1 predates it) and a later migration cannot rescue an earlier one that aborts. Migrations are tracked by version number with no content hash, so this instance — which has already applied 0028 — does not re-run it and keeps the account it created.
The tests fail without the fix, with the real symptom:
migration 0028 failed with user "gitbay-bot" present:
UNIQUE constraint failed: users.username (2067)
When the account is absent the worker now names the cause, and it surfaces
in repo deps status as the check's last error rather than as a stuck
feature with no explanation.