refactor(obs): migrate metrics runtime/schema and tighten migration guards (#2584)

scripts/check_metrics_migration_refs.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+# Allowed references during migration bootstrap (T00 baseline).
+# Keep entries minimal and remove them as callsites are migrated.
+ALLOWLIST=(
+  "crates/obs/src/lib.rs"
+  "crates/obs/src/metrics/mod.rs"
+  "crates/obs/src/metrics/scheduler.rs"
+)
+
+is_allowed_path() {
+  local path="$1"
+  local allow
+  for allow in "${ALLOWLIST[@]}"; do
+    if [[ "$path" == "$allow" ]]; then
+      return 0
+    fi
+  done
+
+  return 1
+}
+
+MATCHES=()
+while IFS= read -r line; do
+  MATCHES+=("$line")
+done < <(
+  cd "$ROOT_DIR"
+  rg -n --no-heading \
+    -e 'rustfs_metrics::' \
+    -e '\binit_metrics_system\b' \
+    -e '\binit_metrics_collectors\b' \
+    rustfs/src crates \
+    --glob '**/*.rs' \
+    --glob '!**/tests/**' \
+    --glob '!docs/**' || true
+)
+
+while IFS= read -r line; do
+  MATCHES+=("$line")
+done < <(
+  cd "$ROOT_DIR"
+  rg -n --no-heading \
+    -e 'rustfs-metrics' \
+    -e 'crates/metrics' \
+    Cargo.toml rustfs crates \
+    --glob '**/*.toml' \
+    --glob '**/*.rs' \
+    --glob '!**/tests/**' \
+    --glob '!docs/**' || true
+)
+
+VIOLATIONS=()
+
+for hit in "${MATCHES[@]}"; do
+  file="${hit%%:*}"
+  if is_allowed_path "$file"; then
+    continue
+  fi
+
+  VIOLATIONS+=("$hit")
+done
+
+if (( ${#VIOLATIONS[@]} > 0 )); then
+  echo "Metrics migration reference guard failed: found non-allowlisted references"
+  printf '%s\n' "${VIOLATIONS[@]}"
+  exit 1
+fi
+
+echo "Metrics migration reference guard passed."