Re-vendor the canonical files from sneak/prompts at dd4027b (closes #171)

.dockerignore, .gitignore, .prettierignore and REPO_POLICIES.md are
copied from sneak/prompts at dd4027b; .editorconfig, check.yml and
.prettierrc already matched. This repository's build artifacts follow
the copied content in .gitignore and, anchored, in .dockerignore. The
scripts follow the new policy: check runs fmt-check, cibuild bootstraps
and runs check before the image build, fmt and fmt-check find the
pinned yarn under nvm, and the image's last stage marks /app safe for
git. The build-context test expects the new pattern forms.

Judgement call: script/precommit runs lint and fmt-check without the tests, so the README's red-phase test commit can still land; the policy allows that form only where local testing is impossible.
Not applicable: the issue's .golangci.yml entries; this TypeScript repository has none.

Model: opus-5-5

script/check

@@ -1,11 +1,8 @@
 #!/bin/sh
-# script/check: run all checks (test, lint). Our own extension to
-# scripts-to-rule-them-all. Both are Docker phases. Must not modify any
-# files.
-#
-# script/fmt-check is not called here, unlike the template: the lint
-# phase already runs `prettier --check .`, so calling it would run
-# prettier a second time over the same tree for the same verdict.
+# script/check: run all checks (test, lint, fmt-check). Our own
+# extension to scripts-to-rule-them-all. test and lint are Docker
+# phases; fmt-check is native, because a formatter writes the working
+# tree. Must not modify any files.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -13,6 +10,7 @@ SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
 main() {
     "$SCRIPT_DIR/test"
     "$SCRIPT_DIR/lint"
+    "$SCRIPT_DIR/fmt-check"
 }
 
 main "$@"

script/cibuild

@@ -1,8 +1,7 @@
 #!/bin/sh
-# script/cibuild: run the CI build. The image's last stage depends on the
-# lint and test phases, so this one build runs eslint, prettier and the
-# suite once each and then compiles. Unlike the template it does not run
-# script/check first, which would run lint and the tests a second time.
+# script/cibuild: run the CI build. It bootstraps first: a CI runner
+# checks out and runs this and nothing else, and script/fmt-check runs
+# the formatter on the host, which a pristine checkout cannot do.
 # --no-cache for the same reason as script/docker: the gate phases the
 # final stage depends on are RUN steps, and a cached one is a check that
 # did not run.
@@ -13,11 +12,12 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
+    "$SCRIPT_DIR/bootstrap"
+    "$SCRIPT_DIR/check"
     # Own line: a failing command substitution inside an argument does
     # not trip `set -e`, so the inline form degrades silently to an
-    # empty constant. The version resolved here goes in as the VERSION
-    # build arg, which takes precedence over what the build would derive
-    # from the .git in its context.
+    # empty constant. The VERSION build argument takes precedence over
+    # the version a build stage derives from the .git in the context.
     version="$(git describe --tags --always --dirty 2>/dev/null || true)"
     [ -n "$version" ] || version="unknown"
     docker build --no-cache \

script/docker

@@ -12,9 +12,8 @@ main() {
     cd "$ROOT"
     # Own line: a failing command substitution inside an argument does
     # not trip `set -e`, so the inline form degrades silently to an
-    # empty constant. The version resolved here goes in as the VERSION
-    # build arg, which takes precedence over what the build would derive
-    # from the .git in its context.
+    # empty constant. The VERSION build argument takes precedence over
+    # the version a build stage derives from the .git in the context.
     version="$(git describe --tags --always --dirty 2>/dev/null || true)"
     [ -n "$version" ] || version="unknown"
     docker build --no-cache \

script/fmt

@@ -4,9 +4,28 @@ set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
+# Must match the pin in script/bootstrap.
+NODE_VERSION="22.17.0"
+
+# script/bootstrap installs node and yarn under nvm and leaves neither
+# on the PATH of the shell that called it, so resolve the pinned
+# toolchain here the way bootstrap's own install step does. nvm is a
+# bash script, hence the subshell.
+run_yarn() {
+    if command -v yarn >/dev/null 2>&1; then
+        exec yarn "$@"
+    fi
+    if [ ! -s "$HOME/.nvm/nvm.sh" ]; then
+        echo "fmt: no yarn; run script/bootstrap first" >&2
+        exit 1
+    fi
+    exec bash -c '. "$HOME/.nvm/nvm.sh" && nvm use "$1" >/dev/null &&
+        shift && exec yarn "$@"' bash "$NODE_VERSION" "$@"
+}
+
 main() {
     cd "$ROOT"
-    yarn run prettier --write .
+    run_yarn run prettier --write .
 }
 
 main "$@"

script/fmt-check

@@ -4,9 +4,28 @@ set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
+# Must match the pin in script/bootstrap.
+NODE_VERSION="22.17.0"
+
+# script/bootstrap installs node and yarn under nvm and leaves neither
+# on the PATH of the shell that called it, so resolve the pinned
+# toolchain here the way bootstrap's own install step does. nvm is a
+# bash script, hence the subshell.
+run_yarn() {
+    if command -v yarn >/dev/null 2>&1; then
+        exec yarn "$@"
+    fi
+    if [ ! -s "$HOME/.nvm/nvm.sh" ]; then
+        echo "fmt-check: no yarn; run script/bootstrap first" >&2
+        exit 1
+    fi
+    exec bash -c '. "$HOME/.nvm/nvm.sh" && nvm use "$1" >/dev/null &&
+        shift && exec yarn "$@"' bash "$NODE_VERSION" "$@"
+}
+
 main() {
     cd "$ROOT"
-    yarn run prettier --check .
+    run_yarn run prettier --check .
 }
 
 main "$@"

script/precommit

@@ -2,17 +2,17 @@
 # script/precommit: run by the git pre-commit hook; fails the commit if
 # checks fail. Our own extension to scripts-to-rule-them-all.
 #
-# Runs lint but deliberately NOT the tests, so the TDD red-phase commit
-# (failing tests, no implementation yet) can land. CI runs
-# script/cibuild, whose image build includes the test phase, and so
-# catches any branch that ships red. The lint phase includes the
-# prettier check, so a badly formatted tree still fails the commit.
+# Runs lint and fmt-check but deliberately NOT the tests, so the TDD
+# red-phase commit (failing tests, no implementation yet) can land. CI
+# runs script/cibuild, which runs the tests, and so catches any branch
+# that ships red.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
 
 main() {
     "$SCRIPT_DIR/lint"
+    "$SCRIPT_DIR/fmt-check"
 }
 
 main "$@"