Deploy main eacf1e7 to prod

Replaces #559, which conflicted.

Model: opus-5-5

script/lint

@@ -1,55 +1,23 @@
 #!/bin/sh
-# script/lint: run the linter. golangci-lint is never installed locally: it
-# runs via docker only, one way, everywhere — script/lint builds
-# Dockerfile.lint, which COPYs the repo into the pinned golangci-lint image
-# and lints as a build step. This works even when the docker daemon is remote
-# and bind mounts are impossible, and it removes the host linter's shared
-# cache, which has attributed other checkouts' findings to this one.
+# script/lint: run the linter. Linting is a phase of the Dockerfile and
+# this builds that phase alone; the linter is never installed or run on
+# a developer host, where a shared result cache and a host-global lock
+# make its answer untrustworthy.
 #
-# --no-cache-filter=lint forces the lint stage to re-execute on every run; a
-# cached lint stage exits 0 in under a second having linted nothing. The deps
-# stage keeps its cache, so module downloads are not repeated.
-# --progress=plain keeps the linter's own output visible on success, so a
-# passing run shows the issue count rather than nothing.
-# --output=type=cacheonly leaves no image behind to clean up.
-#
-# docker silently ignores --no-cache-filter for a stage name that does not
-# match, so a rename or a typo would restore the cached false green with no
-# warning and a fast exit 0. The flag is therefore not trusted: the build
-# output is teed to a log and a run is only a pass if golangci-lint's own
-# summary line ("N issues." / "N issues:") is in it. No summary, no lint,
-# whatever the exit code says.
+# The phase is not the last stage in the file, so it is built only when
+# --target names it. --no-cache because a cached lint layer is a lint
+# that did not run. The tag makes each build replace the previous image
+# instead of leaving a dangling one behind.
 set -eu
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-
-    log="$(mktemp -t webhooker-lint.XXXXXXXX)"
-    rcfile="$(mktemp -t webhooker-lint-rc.XXXXXXXX)"
-    trap 'rm -f "$log" "$rcfile"' EXIT INT TERM
-
-    # The pipeline's status is tee's, and POSIX sh has no pipefail, so the
-    # build's status travels via a file. Output still streams live.
-    {
-        docker build \
-            -f Dockerfile.lint \
-            --no-cache-filter=lint \
-            --progress=plain \
-            --output=type=cacheonly \
-            . 2>&1 && echo 0 >"$rcfile" || echo $? >"$rcfile"
-    } | tee "$log" >&2
-
-    rc="$(cat "$rcfile")"
-    [ "$rc" -eq 0 ] || exit "$rc"
-
-    if ! grep -qE '[0-9]+ issues[.:]' "$log"; then
-        echo "script/lint: golangci-lint printed no summary line; the linter" >&2
-        echo "  did not run. Check that the stage named in --no-cache-filter" >&2
-        echo "  still matches a stage in Dockerfile.lint." >&2
-        exit 1
-    fi
+    docker build --no-cache \
+        --target lint \
+        -t "$("$SCRIPT_DIR/projectname")-lint" .
 }
 
 main "$@"