Add proxy lifecycle shell scripts

Provide a simple way to start, stop, and inspect the host proxy without manual process management.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

status.sh

@@ -0,0 +1,48 @@
+#!/bin/sh
+set -eu
+
+script_dir=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+state_dir="$script_dir/state"
+pid_file="$state_dir/server.pid"
+log_file="$state_dir/server.log"
+config_file="$state_dir/config.env"
+
+host='127.0.0.1'
+port='18765'
+public_url="http://host.docker.internal:${port}"
+
+if [ -f "$config_file" ]; then
+  . "$config_file"
+  host="${GIT_CRED_PROXY_HOST:-$host}"
+  port="${GIT_CRED_PROXY_PORT:-$port}"
+  public_url="${GIT_CRED_PROXY_PUBLIC_URL:-$public_url}"
+fi
+
+printf 'Host listen URL: http://%s:%s\n' "$host" "$port"
+printf 'Container URL: %s\n' "$public_url"
+
+if [ ! -f "$pid_file" ]; then
+  printf 'Status: stopped\n'
+  exit 1
+fi
+
+pid=$(cat "$pid_file" 2>/dev/null || true)
+
+if [ -z "${pid:-}" ] || ! kill -0 "$pid" 2>/dev/null; then
+  printf 'Status: stale pid file\n'
+  exit 1
+fi
+
+printf 'Status: running (pid=%s)\n' "$pid"
+
+if command -v curl >/dev/null 2>&1; then
+  if curl -fsS "http://${host}:${port}/healthz" >/dev/null 2>&1; then
+    printf 'Health: ok\n'
+  else
+    printf 'Health: check failed\n'
+  fi
+fi
+
+if [ -f "$log_file" ]; then
+  printf 'Log file: %s\n' "$log_file"
+fi