style: pass explicit check= to every subprocess.run call

Silences pylint W1510 / ruff PLW1510 across the codebase. The choice
at each site reflects existing intent:

- check=True where the caller implicitly trusts success (docker ps /
  network ls returning stdout, docker build, exec chown/chmod inside
  provisioners).
- check=False where the caller inspects .returncode (race-retry on
  docker run, pipelock sidecar lifecycle, network plumbing, exec_claude
  propagating the session's exit code, best-effort cleanup paths).

No behavior change; check= defaults to False so the False sites are
semantically identical.

tests/_docker.py

@@ -15,6 +15,7 @@ def docker_available() -> bool:
             ["docker", "info"],
             stdout=subprocess.DEVNULL,
             stderr=subprocess.DEVNULL,
+            check=False,
         ).returncode
         == 0
     )

tests/canaries/test_pipelock_image.py

@@ -27,6 +27,7 @@ class TestPipelockImage(unittest.TestCase):
             ["docker", "pull", PIPELOCK_IMAGE],
             stdout=subprocess.DEVNULL,
             stderr=subprocess.DEVNULL,
+            check=False,
         )
         if result.returncode != 0:
             raise unittest.SkipTest(f"could not pull {PIPELOCK_IMAGE}")
@@ -34,7 +35,7 @@ class TestPipelockImage(unittest.TestCase):
     def test_binary_runs(self):
         result = subprocess.run(
             ["docker", "run", "--rm", PIPELOCK_IMAGE, "--version"],
-            capture_output=True, text=True,
+            capture_output=True, text=True, check=False,
         )
         out = result.stdout + result.stderr
         self.assertRegex(out, r"[Pp]ipelock|2\.[0-9]+\.[0-9]+")

tests/integration/test_dry_run_plan.py

@@ -43,6 +43,7 @@ class TestDryRunPlan(unittest.TestCase):
                 env=env,
                 capture_output=True,
                 text=True,
+                check=False,
             )
             self.assertEqual(
                 0, result.returncode,
@@ -83,6 +84,7 @@ class TestDryRunPlan(unittest.TestCase):
             ["docker", "network", "ls", "--format", "{{.Name}}"],
             capture_output=True,
             text=True,
+            check=True,
         )
         return sum(1 for n in result.stdout.splitlines() if n.startswith("claude-bottle"))
 
@@ -91,6 +93,7 @@ class TestDryRunPlan(unittest.TestCase):
             ["docker", "ps", "-a", "--format", "{{.Names}}"],
             capture_output=True,
             text=True,
+            check=True,
         )
         return sum(1 for n in result.stdout.splitlines() if n.startswith("claude-bottle"))
 

tests/integration/test_orphan_cleanup.py

@@ -34,6 +34,7 @@ class TestOrphanCleanup(unittest.TestCase):
                     ["docker", "network", "rm", n],
                     stdout=subprocess.DEVNULL,
                     stderr=subprocess.DEVNULL,
+                    check=False,
                 )
 
     def test_remove_missing_is_noop(self):
@@ -51,7 +52,7 @@ class TestOrphanCleanup(unittest.TestCase):
 
         nets = subprocess.run(
             ["docker", "network", "ls", "--format", "{{.Name}}"],
-            capture_output=True, text=True,
+            capture_output=True, text=True, check=True,
         ).stdout.splitlines()
         self.assertIn(self.internal_name, nets)
         self.assertIn(self.egress_name, nets)
@@ -61,7 +62,7 @@ class TestOrphanCleanup(unittest.TestCase):
 
         nets_after = subprocess.run(
             ["docker", "network", "ls", "--format", "{{.Name}}"],
-            capture_output=True, text=True,
+            capture_output=True, text=True, check=True,
         ).stdout.splitlines()
         self.assertNotIn(self.internal_name, nets_after)
         self.assertNotIn(self.egress_name, nets_after)

tests/integration/test_pipelock_sidecar_smoke.py

@@ -46,6 +46,7 @@ class TestPipelockSidecarSmoke(unittest.TestCase):
             ["docker", "pull", CURL_IMAGE],
             stdout=subprocess.DEVNULL,
             stderr=subprocess.DEVNULL,
+            check=False,
         )
         if result.returncode != 0:
             raise unittest.SkipTest(f"could not pull {CURL_IMAGE}")
@@ -104,6 +105,7 @@ class TestPipelockSidecarSmoke(unittest.TestCase):
             capture_output=True,
             text=True,
             timeout=60,
+            check=False,
         )
         self.assertEqual(
             0, probe.returncode,

tests/unit/test_cli_start_format.py

@@ -38,6 +38,7 @@ class TestStartFormatFlag(unittest.TestCase):
                 env=env,
                 capture_output=True,
                 text=True,
+                check=False,
             )
             self.assertNotEqual(0, result.returncode)
             self.assertIn(