feat(cli): honor BASTION_DIR env var as default for --dir

bastion serve/stop default for --dir was hardcoded to /tmp/lab-bastion.
Now reads BASTION_DIR from env if set, so a deployed bastion daemon
can run from a persistent directory without callers having to pass
--dir on every invocation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

bastion/src/cli/src/commands/serve.ts

@@ -11,7 +11,7 @@ export function registerStartCommand(parent: Command): void {
     .command("start")
     .description("Start the bastion server (HTTP + dnsmasq PXE)")
     .option("--port <port>", "HTTP port", "8080")
-    .option("--dir <dir>", "Bastion data directory", "/tmp/lab-bastion")
+    .option("--dir <dir>", "Bastion data directory", process.env["BASTION_DIR"] ?? "/tmp/lab-bastion")
     .option("--domain <domain>", "Internal domain for hostnames", "ad.itaz.eu")
     .option("--dhcp-mode <mode>", "DHCP mode: proxy or full", "proxy")
     .option("--fedora <version>", "Fedora version", "43")

bastion/src/cli/src/commands/stop.ts

@@ -8,7 +8,7 @@ export function registerStopCommand(parent: Command): void {
   parent
     .command("stop")
     .description("Stop a running bastion server")
-    .option("--dir <dir>", "Bastion data directory", "/tmp/lab-bastion")
+    .option("--dir <dir>", "Bastion data directory", process.env["BASTION_DIR"] ?? "/tmp/lab-bastion")
     .action((opts: { dir: string }) => {
       const pidFile = `${opts.dir}/bastion.pid`;