A lane-literal defect the census cannot see — the literals are
**Set/Array members**, not comparisons — in a live plugin, with **no
test coverage on the filter at all**. That absence is how the inversion
survived.
## The bug
```ts
const ALLOWED_COLUMNS = ["triage", "todo", "in-progress", "in-review", "done", "archived"];
function parseColumns(raw) {
const parsed = raw.split(",").filter(v => ALLOWED_COLUMNS.includes(v));
return parsed.length ? new Set(parsed) : null; // ← `null` ALSO means "no filter requested"
}
```
On a board whose lanes are named anything else, every requested id is
discarded, `parsed.length` is `0`, and the function returns `null` —
**the same value it returns when no filter was requested**. The caller
then does `columns ? all.filter(...) : all`, so the route answers `200`
with the **entire board**.
Asking for one column returns all of them. Nothing in the response says
the filter was dropped. The list also still named `triage`, a column U11
deleted, so it described a board that no longer exists in either
direction.
## The fix
No allow-list can be correct here and none is needed. Valid ids are
whatever the project's workflows declare, and `Task["column"]` is
already `ColumnId = Column | (string & {})` — open by construction.
Filtering directly on the requested ids needs **no resolution source at
all**, which is why this literal, unlike the display ordering in
`cards.ts` (documented DELIBERATE-LITERAL: this package depends on
`@fusion/plugin-sdk` only, so there is no IR or store to resolve from),
is a defect rather than a deferral.
**Deliberate behaviour change:** `?columns=nonsense` now returns an
**empty deck** instead of the whole board. "Show me column X" answered
with every column is not a lenient default — it is the bug wearing a
200.
## Revert proof (measured)
Restore the allow-list and **both** new cases fail:
```
FAIL > filters on a RENAMED lane instead of silently returning the whole board
expected [ { id: 'summary', …(5) }, …(2) ] to have a length of 2 but got 3
FAIL > answers an unknown column with an EMPTY deck, not with everything
expected [ { id: 'summary', …(5) }, …(2) ] to have a length of 1 but got 3
```
Both directions are asserted on purpose: a filter that matched *nothing*
would satisfy the renamed-lane case alone while being equally broken.
## Not changed, and why
`plugins/fusion-plugin-even-cards` carries the **identical** bug — I
wrote the fix there first. It was removed from the pnpm workspace
(`858bab2`, "remove `fusion-plugin-even-cards` from the active workspace
package list to avoid duplicate user-facing integrations") and its
README names this plugin as its replacement, so it is not built, tested,
or shipped by anything. Fixing it would only imply it still runs.
Reverted and left alone.
## Verification
- `pnpm test:gate` — 161 / 487 / 13 / 71 passed
- `pnpm lint` — clean
- `tsc --noEmit` (`@fusion-plugin-examples/even-realities-glasses`) —
clean
- full plugin suite — 188 passed across 19 files
- census `--strict` — exit 0 (unchanged: these literals are Set members,
invisible to it)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
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