fix: remove serial console (root cause of 30s boot delay), enable syslog logging, disk auto-detect

Root cause found: console=ttyS0,115200n8 causes 30-second timeout at every
systemd boot phase on hardware without a physical serial UART. Each phase
transition blocks waiting for the non-existent UART.

Changes:
- Remove console=ttyS0 from kickstart bootloader args and %post setup
- Enable Anaconda syslog forwarding (logging --host --port) for install visibility
- Improve syslog IP→MAC resolution (register from kickstart fetch + progress)
- Fix disk auto-detect: default to empty string (not /dev/sda) for NVMe support
- Enable SysRq magic keys (kernel.sysrq=1) for emergency reboot via JetKVM
- Simplify debug command: remove --sshd flag (inst.sshd always available),
  add /debug-setup.sh HTTP endpoint for nc listener setup
- Add labctl provision logs -f (follow mode with polling)
- Add syslog listener unit tests
- Enable syslog log capture test in integration suite

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

bastion/tests/integration/pxe-provision.test.ts

@@ -224,11 +224,12 @@ describe("PXE boot provisioning", () => {
     // Generate dnsmasq config
     generateDnsmasqConf(config);
 
-    // Start HTTP server
-    const { app, state } = createApp(config);
+    // Start HTTP server + syslog listener
+    const { app, state, syslog } = createApp(config);
     bastionApp = app;
     await app.listen({ port: config.httpPort, host: "0.0.0.0" });
-    log(`Bastion HTTP server listening on :${HTTP_PORT}`);
+    syslog.start();
+    log(`Bastion HTTP server listening on :${HTTP_PORT}, syslog on UDP :${config.syslogPort}`);
 
     // Start dnsmasq (fire-and-forget — it runs until killed)
     // May fail without root (DHCP socket needs CAP_NET_BIND_SERVICE); libvirt network provides DHCP fallback
@@ -387,8 +388,8 @@ describe("PXE boot provisioning", () => {
     expect(data.progress).toBe("complete");
   });
 
-  it.skip("log lines were captured", async () => {
-    // Requires log streamer in %post — skipped until re-added
+  it("syslog install logs were captured", async () => {
+    // Anaconda forwards logs via syslog (logging --host directive in kickstart)
     const res = await fetch(`http://${BASTION_IP}:${HTTP_PORT}/api/logs/${encodeURIComponent(vmMac)}`);
     const data = (await res.json()) as { log_total?: number; log_lines?: Array<{ line: string }> };
     expect(data.log_total).toBeGreaterThan(0);