fix(job): handle SIGTERM and skip static IP for Linux guests

- Install SIGTERM handler that raises KeyboardInterrupt so act_runner
  workflow cancellations trigger the existing VM cleanup path
- Resolve guest_os before the ip_pool block and skip guestinfo IP
  injection for Linux (template doesn't read VMX guestinfo to configure
  network, causing SSH probe to fail against the wrong IP)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ci_orchestrator/commands/job.py

@@ -22,6 +22,7 @@ import shutil
 import subprocess
 import sys
 import tempfile
+import signal
 import time
 import uuid
 from datetime import UTC, datetime
@@ -473,6 +474,12 @@ def job(
     phase_timings: list[tuple[str, float]] = []
     phase_start = _now()
 
+    # SIGTERM (sent by act_runner on workflow cancellation) must trigger cleanup.
+    def _sigterm(_sig: int, _frame: object) -> None:
+        raise KeyboardInterrupt()
+
+    signal.signal(signal.SIGTERM, _sigterm)
+
     click.echo("=" * 60)
     click.echo(f"[job] Job          : {job_id}")
     click.echo(f"[job] Repository   : {repo_url}")
@@ -508,7 +515,14 @@ def job(
             )
             _apply_vmx_overrides(clone_vmx, guest_cpu, guest_memory_mb)
 
-        if config.ip_pool is not None:
+        # Resolve guest OS before IP-pool guard — Linux doesn't read guestinfo IP.
+        if guest_os.lower() == "auto":
+            guest_os = _read_guest_os_from_vmx(clone_vmx)
+            click.echo(f"[job] auto-detected guest OS: {guest_os}")
+        else:
+            guest_os = guest_os.lower()
+
+        if config.ip_pool is not None and guest_os != "linux":
             slot_pool = IpSlotPool(
                 addresses=config.ip_pool.addresses,
                 netmask=config.ip_pool.netmask,
@@ -531,13 +545,6 @@ def job(
         except BackendError as exc:
             raise click.ClickException(f"vmrun start failed: {exc}") from exc
 
-        # Resolve guest OS now that the clone exists.
-        if guest_os.lower() == "auto":
-            guest_os = _read_guest_os_from_vmx(clone_vmx)
-            click.echo(f"[job] auto-detected guest OS: {guest_os}")
-        else:
-            guest_os = guest_os.lower()
-
         deadline = _now() + ready_timeout
         if not _wait_running(backend, handle, deadline, poll_interval):
             raise click.ClickException("timeout waiting for VM to be running.")