## Census
| | column guards |
|---|---|
| before | **69** |
| after | **68** |
## How this was found
By finishing a triage I'd left incomplete. Of the 19 single-guard files,
I had actually examined six and flagged the rest partly on assumption —
so I went back and read them.
Five of the remaining ones turned out to be `archived` comparisons
**pinned by `archived-column-gate-parity.test.ts`** (`audit-ops`,
`task-id-integrity`, `mission-store`, `async-comments-attachments`, plus
`merge-queue-ops-2` for review). Converting any of those moves one of
three encodings that must move together.
**This one isn't pinned**, and that difference is the whole PR.
## What changed
```ts
if (!declaresPreArchiveColumn || preArchiveColumn === archivedColumn
|| preArchiveColumn === "archived")
```
Belt-and-braces: the condition already accepted the resolved lane **or**
the legacy id, stated twice. A set says it once, so the two halves can't
drift apart — the real risk with a duplicated condition, rather than the
census count.
## Why this isn't the split brain
The parity guard pins comparisons of a **task's column** — one of three
encodings of *"an archived task is not live."* This compares a **stored
`preArchiveColumn` value** against the board's archive lane: a different
question, about where to send a card on unarchive.
Verified rather than argued — that suite runs **green** here, and it
went **red** the last time I touched a pinned site (#3076, where I named
an arm and immediately reverted). It's a live check, not an assumption.
## Measured
| check | result |
|---|---|
| archive / artifact / unarchive suites | 7 files, **27 tests green** |
| `archived-column-gate-parity` | **2 passed** |
| five gates + strict census | green |
| core `tsc` | clean |
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>