test: pin the external fixtures and run the suites against the silo binary

The test and verification scripts invoked ./minio and pulled their tooling from
upstream infrastructure with no integrity check. Every `curl | tar` of a client
or an old server binary was an unverified execution path in a script that
regularly runs as a privileged user, and several fetched a floating "latest".

Two installers replace all of it:

- install-mcli.sh resolves a pinned pgsty/mc release, downloads the archive and
  its checksum manifest, requires exactly one valid manifest entry for the
  asset, verifies it, and installs. MCLI_BIN with a mandatory MCLI_SHA256 lets
  an offline or air-gapped run supply its own binary, still checksum-checked.
- install-verified-fixture.sh takes source, expected SHA-256 and target, and
  refuses anything that does not match. Sources may be a URL or a local file.

Every script that previously downloaded mc now calls install-mcli.sh. The three
places that genuinely need an upstream artifact - the old MinIO server binary
for the LDAP IAM upgrade-import test, the 2021 mc for the three-site
replication test, and the functional-tests.sh fixture - go through
install-verified-fixture.sh with the digest recorded inline. Those dl.min.io
URLs remain on purpose: they are historical upstream artifacts needed to prove
upgrade compatibility, and they are now pinned and verified rather than
trusted.

The scripts otherwise switch to ./silo, silo.service, the silo container and
compose service names, and SILO_CONFIG_DIR. run-multi-site-minio-idp.sh is
renamed to run-multi-site-silo-idp.sh with the Makefile target following.
buildscripts/minio-upgrade.sh keeps its name and its `minio server` argv - it
exists to test the MinIO-to-Silo upgrade, so the old side must stay old - but
it is now pinned to an image digest rather than a tag, and its `docker system
prune` and `docker volume prune` calls are removed. Those ran unfiltered
against the developer's whole Docker installation; the resiliency tests had the
same problem and lose their prune and `docker ps -q` sweeps too.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

buildscripts/verify-healing-with-root-disks.sh

@@ -4,20 +4,20 @@ set -E
 set -o pipefail
 set -x
 
-if [ ! -x "$PWD/minio" ]; then
-	echo "minio executable binary not found in current directory"
+if [ ! -x "$PWD/silo" ]; then
+	echo "Silo executable binary not found in current directory"
 	exit 1
 fi
 
 WORK_DIR="$(mktemp -d)"
-MINIO_CONFIG_DIR="$WORK_DIR/.minio"
-MINIO=("$PWD/minio" --config-dir "$MINIO_CONFIG_DIR" server)
+SILO_CONFIG_DIR="$WORK_DIR/.silo"
+SILO=("$PWD/silo" --config-dir "$SILO_CONFIG_DIR" server)
 
-function start_minio() {
+function start_silo() {
 	start_port=$1
 
-	export MINIO_ROOT_USER=minio
-	export MINIO_ROOT_PASSWORD=minio123
+	export MINIO_ROOT_USER=silo
+	export MINIO_ROOT_PASSWORD=silo123
 	unset MINIO_KMS_AUTO_ENCRYPTION # do not auto-encrypt objects
 	unset MINIO_CI_CD
 	unset CI
@@ -28,7 +28,7 @@ function start_minio() {
 	done
 
 	for i in $(seq 1 4); do
-		"${MINIO[@]}" --address ":$((start_port + i))" ${args[@]} 2>&1 >"${WORK_DIR}/server$i.log" &
+		"${SILO[@]}" --address ":$((start_port + i))" ${args[@]} 2>&1 >"${WORK_DIR}/server$i.log" &
 	done
 
 	# Wait until all nodes return 403
@@ -60,7 +60,7 @@ function prepare_block_devices() {
 # Start a distributed MinIO setup, unmount one disk and check if it is formatted
 function main() {
 	start_port=$(shuf -i 10000-65000 -n 1)
-	start_minio ${start_port}
+	start_silo ${start_port}
 
 	# Unmount the disk, after the unmount the device id
 	# /tmp/xxx/mnt/disk4 will be the same as '/' and it
@@ -82,7 +82,7 @@ function main() {
 }
 
 function cleanup() {
-	pkill minio
+	pkill silo
 	sudo umount ${WORK_DIR}/mnt/disk{1..3}/
 	sudo rm /dev/minio-loopdisk*
 	rm -rf "$WORK_DIR"