feat(@scripts): ✨ add mesh-speedtest speed test tool

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

bin/mesh-speedtest

@@ -0,0 +1,113 @@
+#!/bin/sh
+# mesh-speedtest — quick throughput probe across the wg1 mesh.
+#
+# Default: from current host, pull a chunk from each peer over ssh and report
+# Mbps + a streaming verdict. Bytes traverse the wg1 tunnel; ssh adds a thin
+# layer of double-encryption, so numbers run a few % below raw wg throughput
+# but are stable for "can I stream from here?" decisions.
+#
+# Usage:
+#   mesh-speedtest                  # download from each peer (64 MiB)
+#   mesh-speedtest -s 256           # use 256 MiB chunks (slower, more stable)
+#   mesh-speedtest -u               # upload (push to each peer) instead
+#   mesh-speedtest -p plum,black    # restrict to specific peers
+#
+# Peers are the wg1 mesh: apricot, black, plum, quinn-vps. Self is skipped.
+
+set -eu
+
+size_mib=64
+direction=down
+peer_filter=""
+
+while [ $# -gt 0 ]; do
+    case $1 in
+        -s) size_mib=$2; shift 2 ;;
+        -u) direction=up; shift ;;
+        -p) peer_filter=$2; shift 2 ;;
+        -h|--help) sed -n '2,18p' "$0" | sed 's/^# \{0,1\}//'; exit 0 ;;
+        *) echo "unknown arg: $1" >&2; exit 2 ;;
+    esac
+done
+
+all_peers="apricot black plum quinn-vps"
+
+self=$(hostname -s 2>/dev/null || hostname)
+case $self in
+    plum|*plum*) self=plum ;;
+    apricot*) self=apricot ;;
+    black*) self=black ;;
+    quinn-vps*|*1984*) self=quinn-vps ;;
+esac
+
+verdict() {
+    mbps=$1
+    awk -v m="$mbps" 'BEGIN{
+        if (m >= 40) print "4K HDR ok";
+        else if (m >= 25) print "4K ok";
+        else if (m >= 12) print "1080p high ok";
+        else if (m >= 5)  print "1080p ok";
+        else if (m >= 3)  print "720p ok";
+        else if (m >= 1.5) print "480p / rsync first for HD";
+        else print "rsync only";
+    }'
+}
+
+# Run one direction against one peer. Echo "<peer> <mbps> <secs>" or "<peer> ERR".
+probe() {
+    peer=$1
+    bytes=$((size_mib * 1024 * 1024))
+    start=$(date +%s.%N 2>/dev/null || date +%s)
+    if [ "$direction" = down ]; then
+        ssh -o ConnectTimeout=5 -o BatchMode=yes "$peer" \
+            "dd if=/dev/zero bs=1M count=$size_mib status=none" \
+            > /dev/null 2>/tmp/mesh-speedtest.$$.$peer.err || { echo "$peer ERR"; return; }
+    else
+        dd if=/dev/zero bs=1M count=$size_mib status=none 2>/dev/null \
+            | ssh -o ConnectTimeout=5 -o BatchMode=yes "$peer" \
+              "dd of=/dev/null bs=1M status=none" \
+            2>/tmp/mesh-speedtest.$$.$peer.err || { echo "$peer ERR"; return; }
+    fi
+    end=$(date +%s.%N 2>/dev/null || date +%s)
+    secs=$(awk -v s="$start" -v e="$end" 'BEGIN{d=e-s; if(d<0.001)d=0.001; printf "%.3f",d}')
+    mbps=$(awk -v b="$bytes" -v t="$secs" 'BEGIN{printf "%.1f", (b*8)/(t*1000000)}')
+    echo "$peer $mbps $secs"
+}
+
+# Build peer list.
+peers=""
+if [ -n "$peer_filter" ]; then
+    peers=$(echo "$peer_filter" | tr ',' ' ')
+else
+    for p in $all_peers; do
+        [ "$p" = "$self" ] && continue
+        peers="$peers $p"
+    done
+fi
+
+label=$([ "$direction" = down ] && echo "download from" || echo "upload to")
+printf "mesh-speedtest: %s peers, %d MiB chunks (self=%s)\n\n" "$label" "$size_mib" "$self"
+printf "%-12s %10s %8s   %s\n" "peer" "Mbps" "secs" "verdict"
+printf "%-12s %10s %8s   %s\n" "----" "----" "----" "-------"
+
+# Run probes sequentially; parallel would skew Mbps via shared uplink.
+for p in $peers; do
+    out=$(probe "$p")
+    case $out in
+        *ERR)
+            err=$(cat /tmp/mesh-speedtest.$$.$p.err 2>/dev/null | head -1)
+            printf "%-12s %10s %8s   %s\n" "$p" "-" "-" "ssh failed: ${err:-unreachable}"
+            ;;
+        *)
+            peer_n=$(echo "$out" | awk '{print $1}')
+            mbps=$(echo "$out" | awk '{print $2}')
+            secs=$(echo "$out" | awk '{print $3}')
+            v=$(verdict "$mbps")
+            printf "%-12s %10s %8s   %s\n" "$peer_n" "$mbps" "$secs" "$v"
+            ;;
+    esac
+    rm -f /tmp/mesh-speedtest.$$.$p.err
+done
+
+# Average across reachable peers (informational only — wildly different paths).
+echo ""