yak(make-checkverify-format-gate-rewrites-files-instead-of-checking-lnje): make check/verify format gate rewrites files instead of checking

AGENTS.md

@@ -71,7 +71,9 @@ This is a Phoenix Liveview monorepo, the blogging library is in blogex, the appl
 Main make targets:
 
 - `make check` - cheap static gate for both apps (no DB): app `credo --strict` +
-  format, blogex compile (warnings fatal) + format, then `scripts/check-pins.sh`
+  format **check** (`mix format --check-formatted`), blogex compile (warnings
+  fatal) + format **check**, then `scripts/check-pins.sh`. It never rewrites
+  files.
 - `make precommit` - alias of `check`; fast, safe to run on every commit
 - `make test` - both suites (app needs PostgreSQL on localhost:5432)
 - `make verify` - the Lens pass: `check`, then per-app heavy sensors and both suites
@@ -86,6 +88,10 @@ no coverage, about a second. `make precommit` is the same target. Per app,
 `mix precommit` (run inside `app/` or `blogex/`) is the fuller loop: compile with
 warnings fatal, format, test. Run these as often as you like while working.
 
+`make check` never writes files. A formatting failure means run `make format`
+(both apps). The mutating loops are the explicit ones: `make format` and the
+per-app `mix precommit`, which still formats as you work.
+
 **Lens pass (every push, and before handing off).** `make verify` runs `check`
 first (cheapest), then per app: one suite run that exports its coverage, then
 that app's sensors (sobelow, coverage, CRAP, mutation, as those yaks land), which