## What
**Port of #3287 to the sibling tool.** `lifecycle-column-census.mjs
--strict` called `writeBaseline()` during a plain **check**, so running
the gate modified the tree it was checking.
```
clean: 0 files dirty
$ node scripts/lifecycle-column-census.mjs --strict # no --update-baseline
rc=0
after: M scripts/lib/lifecycle-column-census-baseline.json
```
## Why it matters — measured by #3287, reproduced here
#3287 established what this costs: every worker who runs the gate
receives a **byte-identical uncommitted diff they did not author**, and
reasonably commits it. #3283 and #3285 are the same `+0/-1`, five
minutes apart, by two different authors, **neither of whom wrote that
line** — the gate wrote it in both checkouts.
I hit this one the same way, which is the part worth recording: I saw a
modified baseline on my own branch and started reasoning about where
*my* change had touched it. It had not. A check that writes turns every
reader into an author.
The tightening is right in substance, and this tool's `COMMIT IT`
message made the diff *explained* rather than mysterious — better than
fnxc's was. **Neither addresses the mechanism.**
## The shape, matching #3287
Still computed, still reported loudly, written only under an explicit
`--update-baseline` (which has its own path above and is untouched):
```
lifecycle-column-census --strict: baseline CAN BE TIGHTENED — the tree has fewer guards than it allowed
packages/engine/src/scheduler.ts: allows 1, tree has 0
Not written. Record it deliberately, so the diff has one author:
node scripts/lifecycle-column-census.mjs --strict --update-baseline
```
**A plain run stays green rather than failing.** Guard counts drop when
someone *else's* merge removes a literal, so failing on a tightening
would redden main on a change the author never made. Report, don't
enforce — same reasoning #3287 gives for stamps aging into the past.
## Measured, all three directions
| scenario | result |
|---|---|
| plain `--strict`, stale baseline | reports + hint; **tree clean**
(was: 1 file dirty) |
| `--strict --update-baseline` | writes, rc=0 |
| a new guard added | **rc=1** — regression detection intact |
```
lint clean
```
## Note
Claimed on #3287 before starting, since it is that author's fix and they
may have had the port in flight. The two differences from the fnxc case
are noted there: this one fires under `--strict` rather than a bare run
(but `--strict` is what `package.json` and CI invoke, so it is the
common path), and its message was already loud.
65af9fd694