Merge commit 'b639266b0d8852b106709b19162a0dadf1d114f0' into chore/1xfb-5-1-repo-stats

# Conflicts:
#	context/test-evidence/tooling.md

context/code/doc-site.md

@@ -181,6 +181,15 @@ The general form: when a check misses a defect, add the check that could have
 seen it rather than only fixing the defect, and ask what *question* the
 existing check was answering.
 
+**`site/` is build output and is not tracked** (improvise-1xfb.4). It is
+`web/assemble.sh`'s default `OUT_DIR`, and `site/docs` is this script's.
+Every reader builds its own copy from source: CI's `build` job runs
+`nix build .#site`, which assembles into the store; the harness assembles
+into `harness/serve/`; `scripts/build-web-release.sh` assembles into a
+temporary stage. For a while 27 generated pages under `site/docs` were
+committed by accident. They went stale, still saying 12 categories after the
+cap was raised, and nothing read them.
+
 ## 5. Why a node script and not a generator
 
 The landing page is hand-written HTML with no build step and one pinned CDN