Merge and Split both 500ed. The audit note each writes uses `source = 'system'`
and the column is `enum('web','email')`, so the insert threw inside the
transaction and nothing committed — which is why the operator saw no state change
at all rather than a half-done merge.
Widened to an enum rather than a varchar, and the reasoning is the same test that
made `tickets.status` a varchar in `2026_04_17_000002`: statuses became
operator-definable rows, so their domain is open. `source` is the opposite — all
three values are set by code, an operator can never add a fourth, and the enum is
what keeps a typo'd source loud instead of a silently unfilterable row.
`TicketMessage::system()` is now the only place a system note is written. Three
scattered literals is how this reopens.
A SECOND 500 ON THE SAME ACTION, unreported and one longer title away. `split()`
appended ' (split)' to a title the product validates at max:255, so splitting a
full-length title produced 263 characters and the identical hard failure. Bounded
at the write rather than widened, and the distinction is written down: widen when
the data is right and the column is wrong; bound when the column expresses a real
product rule. 255 is the product's own limit, so a 263-character title would be
un-editable forever — the edit form would bounce it every time.
And `split()` now honours its own comment. Line 682 has always said "exclude
system notes" while the code copied them; it never mattered because no system row
could exist. The moment the enum accepts them, splitting a merged ticket would
carry "Merged from ticket QAX-0005." onto a ticket that was never merged.
Joel Wedemire
ef4d0c4f93