Add tmux demo driver and table variant of egress IP check

run-demo.sh opens a 2x2 tmux grid: egress-IP table looping in a
netshoot pod, kubectl get px watch, and both create scripts running
with COUNT (default 4) proxies. show-egress-ips-table.sh is the
pane-sized one-line-per-proxy variant used by the driver.

Co-Authored-By: Claude <noreply@anthropic.com>

docs/demo/run-demo.sh

@@ -0,0 +1,67 @@
+#!/bin/bash
+# Demo driver: opens a tmux session with a 2x2 pane grid:
+#
+#   top-left:     show-egress-ips-table.sh in a 10s loop, run inside the
+#                 netshoot pod against the in-cluster discovery Service
+#   top-right:    watch -n3 kubectl get px
+#   bottom-left:  create-kubernetes-proxies.sh <count>
+#   bottom-right: create-gcp-proxies.sh <count>
+#
+# Usage:
+#   ./run-demo.sh
+#
+# Optional environment:
+#   COUNT         proxies each create script makes (default: 4)
+#   SESSION       tmux session name (default: proxy-demo; an existing
+#                 session with this name is killed and recreated)
+#   NETSHOOT_POD  pod to exec into for the egress-IP loop (default: netshoot)
+#   DEMO_DIR      where the demo scripts live (default: this script's dir)
+set -euo pipefail
+
+COUNT="${COUNT:-4}"
+SESSION="${SESSION:-proxy-demo}"
+NETSHOOT_POD="${NETSHOOT_POD:-netshoot}"
+DEMO_DIR="${DEMO_DIR:-$(cd "$(dirname "$0")" && pwd)}"
+BASE_URL="http://egress-proxies-operator-controller-manager-discovery-service.egress-proxies-operator-system.svc.cluster.local:8090"
+
+for tool in tmux kubectl; do
+    if ! command -v "${tool}" &> /dev/null; then
+        echo "ERROR: ${tool} is required but not installed" >&2
+        exit 1
+    fi
+done
+
+if ! kubectl get pod "${NETSHOOT_POD}" &> /dev/null; then
+    echo "ERROR: pod ${NETSHOOT_POD} not found — start one with:" >&2
+    echo "  kubectl run netshoot --image=nicolaka/netshoot -- sleep infinity" >&2
+    exit 1
+fi
+
+echo "Copying show-egress-ips-table.sh into pod ${NETSHOOT_POD} ..."
+kubectl cp "${DEMO_DIR}/show-egress-ips-table.sh" "${NETSHOOT_POD}:/tmp/show-egress-ips-table.sh"
+
+if tmux has-session -t "${SESSION}" 2> /dev/null; then
+    echo "Killing existing tmux session ${SESSION}"
+    tmux kill-session -t "${SESSION}"
+fi
+
+# 2x2 grid: after these splits pane indexes are 0 top-left, 1 top-right,
+# 2 bottom-left, 3 bottom-right; tiled layout evens them into quarters.
+tmux new-session -d -s "${SESSION}"
+tmux split-window -h -t "${SESSION}:0"
+tmux split-window -v -t "${SESSION}:0.0"
+tmux split-window -v -t "${SESSION}:0.1"
+tmux select-layout -t "${SESSION}:0" tiled
+
+loop_cmd="BASE_URL=${BASE_URL}; while true; do bash /tmp/show-egress-ips-table.sh \"\$BASE_URL\"; echo; sleep 10; done"
+tmux send-keys -t "${SESSION}:0.0" "kubectl exec -it ${NETSHOOT_POD} -- bash -c '${loop_cmd}'" C-m
+tmux send-keys -t "${SESSION}:0.1" "watch -n3 kubectl get px" C-m
+tmux send-keys -t "${SESSION}:0.2" "bash ${DEMO_DIR}/create-kubernetes-proxies.sh ${COUNT}" C-m
+tmux send-keys -t "${SESSION}:0.3" "bash ${DEMO_DIR}/create-gcp-proxies.sh ${COUNT}" C-m
+
+tmux select-pane -t "${SESSION}:0.2"
+if [ -n "${TMUX:-}" ]; then
+    tmux switch-client -t "${SESSION}"
+else
+    tmux attach-session -t "${SESSION}"
+fi