Add Arch mirror manager: benchmark, apply, pin, restore, status

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QKxGW1raAWaqeU8WdHsMsp

bin/omarchy-cn-mirror-benchmark

@@ -0,0 +1,27 @@
+#!/bin/bash
+# omarchy:summary=Benchmark Arch mirrors for speed, latency, and sync freshness
+# omarchy:examples=omarchycn mirror benchmark
+
+set -euo pipefail
+
+source "$OMARCHY_PATH/cn/lib/mirror.sh"
+
+printf '%-11s %-22s %12s %8s %10s\n' "ID" "NAME" "SPEED" "TTFB" "SYNC"
+
+for id in $(cn_mirror_ids); do
+  url=$(cn_mirror_url "$id")
+  read -r speed ttfb age < <(cn_mirror_probe "$url")
+
+  if (( speed > 0 )); then
+    speed_h="$((speed / 1024)) KB/s"
+  else
+    speed_h="FAIL"
+  fi
+  case "$age" in
+  stale) sync_h="STALE" ;;
+  unknown) sync_h="?" ;;
+  *) sync_h="$((age / 60))m ago" ;;
+  esac
+
+  printf '%-11s %-22s %12s %7ss %10s\n' "$id" "$(cn_mirror_name "$id")" "$speed_h" "${ttfb:0:5}" "$sync_h"
+done