TOOL-9: pin checks print their FAIL line under pipefail; job tokens via header

A missing or comment-only .gitea/infra-pin now ends on the workflow's own
FAIL line instead of git's `fatal: path ... does not exist` (still red). Every
x-access-token remote URL becomes an env-set Authorization header, so no
token lands in .git/config or argv; the pin workflows' temp dir is removed
by an EXIT trap, also on failure.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/infra-pin.yml

@@ -23,16 +23,20 @@ jobs:
           INFRA_TOKEN: ${{ secrets.INFRA_READ_TOKEN }}   # admin/goodwe is private
         run: |
           set -eu
-          D=$(mktemp -d) && cd "$D"
-          git init -q . && git remote add origin "$(echo "$SELF" | sed "s#://#://x-access-token:${TOKEN}@#")"
+          D=$(mktemp -d) && trap 'cd / && rm -rf "$D"' EXIT && cd "$D"
+          git init -q .
           # The pin of the commit this event is about (the PR head, or the push).
-          git fetch -q --depth 1 origin "$GITHUB_SHA"
-          PIN=$(git show FETCH_HEAD:.gitea/infra-pin | grep -v '^#' | tr -d '[:space:]')
+          # Token as an env-set header: not in argv or .git/config (TOOL-9).
+          GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=http.extraHeader GIT_CONFIG_VALUE_0="Authorization: token $TOKEN" \
+            git fetch -q --depth 1 "$SELF" "$GITHUB_SHA" || { echo "FAIL: could not fetch $GITHUB_SHA here."; exit 1; }
+          # `|| true`: under the runner's pipefail a missing or comment-only pin
+          # would stop here on git's error instead of the FAIL line below (TOOL-9).
+          PIN=$(git show FETCH_HEAD:.gitea/infra-pin | grep -v '^#' | tr -d '[:space:]') || true
+          test -n "$PIN" || { echo "FAIL: .gitea/infra-pin is missing at $GITHUB_SHA, or holds only comments."; exit 1; }
           test -n "$INFRA_TOKEN" || { echo "FAIL: secret INFRA_READ_TOKEN is not available to this run (a fork PR?)."; exit 1; }
           # Header via env, as in checks.yml: the token stays out of argv.
           HEAD=$(GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=http.extraHeader GIT_CONFIG_VALUE_0="Authorization: token $INFRA_TOKEN" \
-            git ls-remote "$INFRA" refs/heads/release/1.0 | cut -f1)
-          cd / && rm -rf "$D"
+            git ls-remote "$INFRA" refs/heads/release/1.0 | cut -f1) || true
           test -n "$HEAD" || { echo "FAIL: could not read admin/goodwe release/1.0."; exit 1; }
           if [ "$PIN" != "$HEAD" ]; then
             echo "STALE: .gitea/infra-pin is $PIN but admin/goodwe release/1.0 is $HEAD."