diff --git a/.github/actionlint.yaml b/.github/actionlint.yaml
new file mode 100644
index 0000000000..dbd43187c2
--- /dev/null
+++ b/.github/actionlint.yaml
@@ -0,0 +1,5 @@
+# Source validation only; labels do not attest runtime isolation.
+self-hosted-runner:
+  labels:
+    - cwlab-ci-isolated
+    - cwlab-control
diff --git a/.github/workflows/codeql-pr.yml b/.github/workflows/codeql-pr.yml
index 356244f7fc..1be7ae0449 100644
--- a/.github/workflows/codeql-pr.yml
+++ b/.github/workflows/codeql-pr.yml
@@ -60,7 +60,9 @@ jobs:
     name: Detect CodeQL languages
     # Draft PRs get no runner; ready_for_review re-runs this on the same head.
     if: (github.event.action != 'closed') && (github.event.pull_request.draft != true || github.event.action == 'converted_to_draft' || github.event.action == 'closed')
-    runs-on: ${{ fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '"ubuntu-24.04"') }}
+    runs-on:
+      group: ${{ (fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '{"group":"CWL CI isolated","labels":["self-hosted","linux","x64","cwlab-ci-isolated"]}')).group }}
+      labels: ${{ (fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '{"group":"CWL CI isolated","labels":["self-hosted","linux","x64","cwlab-ci-isolated"]}')).labels }}
     timeout-minutes: 5
     permissions:
       contents: read
@@ -164,7 +166,9 @@ jobs:
     # dependency exactly; the only case where it's genuinely skipped is a
     # closed PR, where this job being implicitly skipped too is fine because
     # closed PRs need no required check.
-    runs-on: ${{ fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '"ubuntu-24.04"') }}
+    runs-on:
+      group: ${{ (fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '{"group":"CWL CI isolated","labels":["self-hosted","linux","x64","cwlab-ci-isolated"]}')).group }}
+      labels: ${{ (fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '{"group":"CWL CI isolated","labels":["self-hosted","linux","x64","cwlab-ci-isolated"]}')).labels }}
     # Verdict reads have exceeded five minutes; retain the ten-minute control budget.
     timeout-minutes: 10
     permissions:
@@ -367,7 +371,9 @@ jobs:
       && github.event.pull_request.state != 'closed'
       && needs.detect-languages.result == 'success'
       && needs.detect-languages.outputs.code == 'true'
-    runs-on: ${{ fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '"ubuntu-24.04"') }}
+    runs-on:
+      group: ${{ (fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '{"group":"CWL CI isolated","labels":["self-hosted","linux","x64","cwlab-ci-isolated"]}')).group }}
+      labels: ${{ (fromJSON(github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main' && '{"group":"CWL central control","labels":["self-hosted","linux","x64"]}' || '{"group":"CWL CI isolated","labels":["self-hosted","linux","x64","cwlab-ci-isolated"]}')).labels }}
     timeout-minutes: 5
     permissions:
       contents: read
diff --git a/.github/workflows/package-description-boundary.yml b/.github/workflows/package-description-boundary.yml
index 1bd4cc9926..8241893628 100644
--- a/.github/workflows/package-description-boundary.yml
+++ b/.github/workflows/package-description-boundary.yml
@@ -61,7 +61,11 @@ permissions:
 
 jobs:
   build-distribution:
-    runs-on: ubuntu-latest
+    # Caller-controlled build backends run only on the disposable isolated pool.
+    # Never fall back to a GitHub-hosted runner for untrusted package code.
+    runs-on:
+      group: CWL CI isolated
+      labels: [self-hosted, linux, x64, cwlab-ci-isolated]
     timeout-minutes: 10
     steps:
       - name: Check out the calling repository
@@ -127,7 +131,11 @@ jobs:
   package-description-boundary:
     needs: build-distribution
     if: ${{ always() }}
-    runs-on: ubuntu-latest
+    # The trusted inspector also stays on the isolated pool. Missing capacity
+    # must remain an incomplete check, never a hosted fallback or silent pass.
+    runs-on:
+      group: CWL CI isolated
+      labels: [self-hosted, linux, x64, cwlab-ci-isolated]
     timeout-minutes: 10
     steps:
       - name: Reject a failed input producer
diff --git a/docs/doctoring/package-description-boundary.md b/docs/doctoring/package-description-boundary.md
index 1121809d96..fb6f52296f 100644
--- a/docs/doctoring/package-description-boundary.md
+++ b/docs/doctoring/package-description-boundary.md
@@ -167,3 +167,18 @@ metadata descriptions must be identical or the gate fails closed. Published Mark
 links using GitHub's `blob/main`, `tree/main`, `master`, or `develop` forms are
 blocking `mutable-release-link` findings; release tags and exact commits remain
 valid.
+
+## Runner boundary
+
+Both jobs in `.github/workflows/package-description-boundary.yml` now require
+`CWL CI isolated` with `self-hosted`, `linux`, `x64`, and
+`cwlab-ci-isolated` labels. The producer executes caller-controlled packaging
+code; the inspector executes the trusted central gate. Neither job has a
+GitHub-hosted fallback. Missing isolated capacity therefore remains incomplete
+hosted evidence and cannot become a silent pass.
+
+This is a package-gate slice of the broader all-workflow migration owned by
+`ContextualWisdomLab/.github#2565`. It does not provision runners, widen group
+access, or prove disposable cleanup. A real caller can be accepted only after
+operator-provided group access, isolated capacity, cleanup canary, and fresh
+exact-head terminal checks.
diff --git a/tests/test_audit_org_codeql_coverage.py b/tests/test_audit_org_codeql_coverage.py
index 0ffc8fa749..194540ad53 100644
--- a/tests/test_audit_org_codeql_coverage.py
+++ b/tests/test_audit_org_codeql_coverage.py
@@ -263,9 +263,13 @@ def test_null_latest_analysis_is_not_coverage() -> None:
 
 
 def test_audit_codeql_coverage_defaults_now_to_current_time() -> None:
-    repositories = [covered_by_recent_analysis("DefaultNowRepo", days_ago=0)]
+    """Exercise the real default clock with a genuinely current analysis."""
+    repository = covered_by_recent_analysis("DefaultNowRepo", days_ago=0)
+    repository["latest_codeql_analysis"]["created_at"] = datetime.now(
+        timezone.utc
+    ).isoformat()
 
-    assert audit.audit_codeql_coverage(repositories) == []
+    assert audit.audit_codeql_coverage([repository]) == []
 
 
 def test_load_payload_reads_from_stdin(monkeypatch) -> None:
@@ -299,7 +303,17 @@ def test_main_fail_path_reports_gaps_from_stdin(monkeypatch, capsys) -> None:
     assert "FAIL: 1 repositories have no CodeQL coverage" in captured.err
 
 
-def test_main_pass_path_reports_from_file_arg(tmp_path, capsys) -> None:
+def test_main_pass_path_reports_from_file_arg(tmp_path, capsys, monkeypatch) -> None:
+    """Keep the CLI freshness witness bound to the fixture's reference clock."""
+    class FixedDatetime(datetime):
+        """Supply the same reference instant used by the analysis fixture."""
+
+        @classmethod
+        def now(cls, tz=None):
+            """Return the fixture clock in the caller's requested timezone."""
+            return NOW.astimezone(tz) if tz is not None else NOW.replace(tzinfo=None)
+
+    monkeypatch.setattr(audit, "datetime", FixedDatetime)
     payload_path = tmp_path / "repositories.json"
     payload_path.write_text(
         json.dumps([covered_by_default_setup("ELUNVERA"), covered_by_recent_analysis("Orgmetra")]),
diff --git a/tests/test_codeql_pr_workflow_contract.py b/tests/test_codeql_pr_workflow_contract.py
index 82569e89c7..c19cac190f 100644
--- a/tests/test_codeql_pr_workflow_contract.py
+++ b/tests/test_codeql_pr_workflow_contract.py
@@ -1147,10 +1147,10 @@ def test_codeql_moved_head_requires_forward_ancestry(tmp_path: Path) -> None:
         assert enforce.returncode != 0
 
 
-def test_codeql_control_routing_keeps_pr_workflows_hosted() -> None:
+def test_codeql_control_routing_keeps_pr_workflows_isolated() -> None:
     """Only the trusted main revision may request the restricted control group."""
     workflow = WORKFLOW_PATH.read_text(encoding="utf-8")
-    selectors = [line.strip() for line in workflow.splitlines() if line.strip().startswith("runs-on:")]
+    selectors = [line.strip() for line in workflow.splitlines() if line.startswith("      group:")]
     trusted = "ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main"
     assert len(selectors) == 3
     for selector in selectors:
@@ -1158,7 +1158,10 @@ def test_codeql_control_routing_keeps_pr_workflows_hosted() -> None:
         choices = re.findall(r"'([^']*)'", selector)
         assert choices[0] == trusted
         assert json.loads(choices[1]) == {"group": "CWL central control", "labels": ["self-hosted", "linux", "x64"]}
-        assert json.loads(choices[2]) == "ubuntu-24.04"
+        assert json.loads(choices[2]) == {
+            "group": "CWL CI isolated",
+            "labels": ["self-hosted", "linux", "x64", "cwlab-ci-isolated"],
+        }
 
 
 def test_codeql_pr_rejects_invalid_required_run_time(tmp_path: Path) -> None:
diff --git a/tests/test_package_description_boundary.py b/tests/test_package_description_boundary.py
index f2adf26a3b..78bb267712 100644
--- a/tests/test_package_description_boundary.py
+++ b/tests/test_package_description_boundary.py
@@ -341,6 +341,20 @@ def test_workflow_is_callable_only() -> None:
     assert set(_workflow()[True]) == {"workflow_call"}
 
 
+def test_workflow_runner_is_central_isolated_self_hosted() -> None:
+    """Both jobs reject GitHub-hosted fallback and use the isolated pool."""
+    jobs = _workflow()["jobs"]
+    expected = {
+        "group": "CWL CI isolated",
+        "labels": ["self-hosted", "linux", "x64", "cwlab-ci-isolated"],
+    }
+    assert jobs["build-distribution"]["runs-on"] == expected
+    assert jobs["package-description-boundary"]["runs-on"] == expected
+    text = _WORKFLOW.read_text(encoding="utf-8")
+    assert "ubuntu-latest" not in text
+    assert "ubuntu-24.04" not in text
+
+
 def test_workflow_checks_out_the_gate_at_its_own_commit() -> None:
     """The caller must run the gate revision it pinned, not whatever main holds."""
     steps = _workflow()["jobs"]["package-description-boundary"]["steps"]
diff --git a/tests/test_required_review_runner_image_contract.py b/tests/test_required_review_runner_image_contract.py
index ab7ede7aa4..b299244ad7 100644
--- a/tests/test_required_review_runner_image_contract.py
+++ b/tests/test_required_review_runner_image_contract.py
@@ -95,10 +95,17 @@ def test_opencode_review_dispatch_uses_explicit_supported_image(self) -> None:
     unittest.main()
 
 
-def test_codeql_pr_routes_trusted_main_to_control_and_pr_revisions_to_hosted() -> None:
-    """Separate short metadata work from model work without granting PR runner access."""
+def test_codeql_pr_routes_trusted_main_to_control_and_pr_revisions_to_isolated() -> None:
+    """Keep trusted workflow control separate from isolated PR execution."""
     workflow = Path(".github/workflows/codeql-pr.yml").read_text()
-    assert workflow.count('"group":"CWL central control"') == 3
-    assert workflow.count("github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main'") == 3
-    assert workflow.count("|| '\"ubuntu-24.04\"'") == 3
+    trusted = "github.workflow_ref == 'ContextualWisdomLab/.github/.github/workflows/codeql-pr.yml@refs/heads/main'"
+    selectors = [line for line in workflow.splitlines() if line.startswith("      group:")]
+    labels = [line for line in workflow.splitlines() if line.startswith("      labels:")]
+    assert len(selectors) == len(labels) == 3
+    for selector, label in zip(selectors, labels, strict=True):
+        assert trusted in selector and trusted in label
+        assert '"group":"CWL central control"' in selector
+        assert '"group":"CWL CI isolated"' in selector
+        assert '"cwlab-ci-isolated"' in selector and '"cwlab-ci-isolated"' in label
+        assert '"ubuntu-24.04"' not in selector + label
     assert '"group":"CWL MCP remediation"' not in workflow
diff --git a/tests/test_sandboxed_web_e2e.py b/tests/test_sandboxed_web_e2e.py
index 1b1cdf3722..e43aed95e0 100644
--- a/tests/test_sandboxed_web_e2e.py
+++ b/tests/test_sandboxed_web_e2e.py
@@ -1581,6 +1581,8 @@ def test_isolated_command_resolves_repo_local_launcher_against_sandboxed_cwd(mon
     resolution instead goes through the sandboxed-``cwd``-relative path this
     fix adds, not a PATH search.
     """
+    # Model the guest home independently of the host scratch directory.
+    monkeypatch.setattr(Path, "home", lambda: tmp_path / "synthetic-home")
     monkeypatch.setattr(sandboxed_web_e2e.shutil, "which", lambda *_args, **_kwargs: None)
     sandbox = tmp_path / "sandbox"
     repo = sandbox / "repo"
@@ -1613,6 +1615,8 @@ def test_isolated_command_resolves_bare_command_via_relative_path_entry(monkeypa
     ``shutil.which`` to ``None`` here proves resolution instead falls
     through to the cwd-anchored ``PATH`` search this fix adds.
     """
+    # Model the guest home independently of the host scratch directory.
+    monkeypatch.setattr(Path, "home", lambda: tmp_path / "synthetic-home")
     monkeypatch.setattr(sandboxed_web_e2e.shutil, "which", lambda *_args, **_kwargs: None)
     sandbox = tmp_path / "sandbox"
     repo = sandbox / "repo"
@@ -1646,6 +1650,8 @@ def test_isolated_command_translates_absolute_workspace_launcher_to_sandbox_moun
     that does not exist inside the sandbox, where only ``SANDBOX_MOUNT`` is
     bound, so the command would fail to launch there unchanged.
     """
+    # Model the guest home independently of the host scratch directory.
+    monkeypatch.setattr(Path, "home", lambda: tmp_path / "synthetic-home")
     monkeypatch.setattr(sandboxed_web_e2e.shutil, "which", lambda *_args, **_kwargs: None)
     sandbox = tmp_path / "sandbox"
     repo = sandbox / "repo"
@@ -1706,6 +1712,8 @@ def test_isolated_command_rejects_relative_path_entry_escaping_sandbox(monkeypat
 
 def test_isolated_command_rejects_repo_local_path_traversal(monkeypatch, tmp_path):
     """A repo-local launcher path that lexically escapes the sandbox root is still rejected."""
+    # Model the guest home independently of the host scratch directory.
+    monkeypatch.setattr(Path, "home", lambda: tmp_path / "synthetic-home")
     monkeypatch.setattr(sandboxed_web_e2e.shutil, "which", lambda *_args, **_kwargs: None)
     sandbox = tmp_path / "sandbox"
     repo = sandbox / "repo"
@@ -1726,6 +1734,8 @@ def test_isolated_command_rejects_repo_local_path_traversal(monkeypatch, tmp_pat
 
 def test_isolated_command_rejects_explicit_external_path(monkeypatch, tmp_path):
     """An explicit absolute path outside the workspace and bind roots is still rejected."""
+    # Model the guest home independently of the host scratch directory.
+    monkeypatch.setattr(Path, "home", lambda: tmp_path / "synthetic-home")
     monkeypatch.setattr(sandboxed_web_e2e.shutil, "which", lambda *_args, **_kwargs: None)
     sandbox = tmp_path / "sandbox"
     repo = sandbox / "repo"
diff --git a/tests/test_scheduler_and_codeql_dispatch_runner_image_contract.py b/tests/test_scheduler_and_codeql_dispatch_runner_image_contract.py
index 42efce621e..d6cd65c9de 100644
--- a/tests/test_scheduler_and_codeql_dispatch_runner_image_contract.py
+++ b/tests/test_scheduler_and_codeql_dispatch_runner_image_contract.py
@@ -49,12 +49,12 @@ def test_hourly_review_repair_uses_explicit_supported_image(self) -> None:
         self.assertIn("labels: [self-hosted, linux, x64]", workflow)
 
     def test_codeql_pr_uses_explicit_supported_image(self) -> None:
-        """Require trusted-main control routing and Ubuntu fallback for all three jobs."""
+        """Require trusted-main control routing and isolated fallback for all three jobs."""
         workflow = CODEQL_PR.read_text(encoding="utf-8")
         self.assertNotIn("runs-on: ubuntu-latest", workflow)
         selectors = [
             line.strip() for line in workflow.splitlines()
-            if line.strip().startswith("runs-on:")
+            if line.startswith("      group:")
         ]
         self.assertEqual(len(selectors), 3)
         for selector in selectors:
@@ -64,7 +64,7 @@ def test_codeql_pr_uses_explicit_supported_image(self) -> None:
             )
             self.assertIn('"group":"CWL central control"', selector)
             self.assertIn('"labels":["self-hosted","linux","x64"]', selector)
-            self.assertIn("|| '\"ubuntu-24.04\"'", selector)
+            self.assertIn("|| '{\"group\":\"CWL CI isolated\",\"labels\":[\"self-hosted\",\"linux\",\"x64\",\"cwlab-ci-isolated\"]}'", selector)
 
     def test_codeql_scan_dispatch_uses_explicit_supported_image(self) -> None:
         """Require validation, scan, and attempt wake jobs in the dedicated group."""