tests: add bluejay-ws runner-exclusion lint + fix 3 stale runner-fleet assertions

Adds Runners_MustNotPinToOperatorWorkstationHosts lint test enforcing
operator directive 2026-05-26: BLUEJAY-WS / iamworkin-ws must never be
a fleet GitHub Actions runner. Build-side analog of the Sprint 9 NEW
safe-account exclusion gate (Puppet GPO/AppLocker/WDAC/audit-forwarder
modules refuse to apply on BLUEJAY-WS). Scans every github-runner
Deployment for forbidden nodeName, nodeSelector, nodeAffinity match
expressions, and toleration key/value pinning. See CLAUDE.md "Common
Mistakes" entry and feedback_bluejay_ws_never_public_runner.md.

Also fixes 3 pre-existing GitHubRunnerFleet_* lint failures that broke
when the runner image bumped to v20260525-ruby3.3.11-stepca (added a
setup-runner-home initContainer):

  * Add MainContainerMappings() helper (containers only, excludes
    initContainers) and switch
    GitHubRunnerFleet_MustRegisterRequiredReposAsRepoScopedDeployments
    + GitHubRunnerFleet_MustSetWritableNonRootDotnetAndCachePaths
    over to it. Without this, ContainerMappings().Should().ContainSingle()
    found the initContainer + runner = 2 containers and failed.

  * Loosen GitHubRunnerFleet_MustAvoidRwoMultiAttachForScaledDeployments
    ReplicaCount assertion from Be(2) to BeGreaterOrEqualTo(2). The
    semantic invariant is "at least 2 replicas so no single-pod
    bottleneck"; deployments tuned upward per 14d CI activity (e.g.
    github-runner-print-web at replicas: 3, see commit 1f1f682 PR #24)
    are valid.

Lint baseline: 6 failed -> 3 failed (the 3 remaining are unrelated:
PublicReadWriteIngressRoutes_* lives in FlowerCore.Updater/k8s/
ingressroute.yaml — separate PR; FcDeviceManagement_* needs operator
domain decision on the missing apps/fc-devicemgmt/argocd-application.yaml).

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

tests/bluejay-infra-lint/FleetManifestLintTests.cs

@@ -236,7 +236,7 @@ public sealed class FleetManifestLintTests
         {
             deployments.Should().ContainKey(expectedRunner.Key);
 
-            var container = deployments[expectedRunner.Key].ContainerMappings().Should().ContainSingle().Subject;
+            var container = deployments[expectedRunner.Key].MainContainerMappings().Should().ContainSingle().Subject;
             EnvValue(container, "REPO_URL").Should().Be(expectedRunner.Value);
             EnvValue(container, "EPHEMERAL").Should().Be("true");
             EnvValue(container, "LABELS").Should().Be("self-hosted,linux,fc-build-linux");
@@ -252,7 +252,7 @@ public sealed class FleetManifestLintTests
     {
         foreach (var deployment in GitHubRunnerDeployments().Values)
         {
-            var container = deployment.ContainerMappings().Should().ContainSingle().Subject;
+            var container = deployment.MainContainerMappings().Should().ContainSingle().Subject;
 
             foreach (var expectedEnv in WritableRunnerEnv)
             {
@@ -279,7 +279,10 @@ public sealed class FleetManifestLintTests
         foreach (var deploymentName in ScaledLinuxRunnerDeployments)
         {
             var deployment = deployments[deploymentName];
-            ReplicaCount(deployment).Should().Be(2);
+            // Scaled runners must have >= 2 replicas (avoid single-pod bottleneck).
+            // Individual deployments may be tuned upward per CI activity — see
+            // "runners: right-size replica counts per 14d CI activity (#24)".
+            ReplicaCount(deployment).Should().BeGreaterOrEqualTo(2, $"{deploymentName} is in the scaled set and must run with at least 2 replicas");
 
             var volumes = deployment.MappingSequence("spec", "template", "spec", "volumes");
             var claimNames = volumes
@@ -305,6 +308,108 @@ public sealed class FleetManifestLintTests
             .Be("github-runner-nuget-cache");
     }
 
+    [Fact]
+    public void Runners_MustNotPinToOperatorWorkstationHosts()
+    {
+        // CRITICAL SAFETY (operator directive 2026-05-26): BLUEJAY-WS is the
+        // operator's primary workstation — host of the 1Password Connect
+        // bearer token, fcadmin SSH keys to noc1, signing CA private keys,
+        // and source for every FC repo. A self-hosted GitHub Actions runner
+        // there would execute arbitrary PR code with that local access.
+        // Build-side analog of the Sprint 9 NEW safe-account exclusion gate
+        // (Puppet GPO/AppLocker/WDAC/audit-forwarder modules refuse to apply
+        // on BLUEJAY-WS). This lint asserts no GitHub-runner Deployment in
+        // apps/github-runner/ pins to a forbidden operator-workstation host
+        // via nodeName, nodeSelector, nodeAffinity, or tolerations.
+        // Existing legacy `bluejay-ws-sandbox-1` GitHub-registered runner is
+        // out of scope here (it's a runtime registration, not a K8s
+        // Deployment) — see CLAUDE.md "Common Mistakes" entry and
+        // feedback_bluejay_ws_never_public_runner.md.
+        var forbiddenHostPatterns = new[]
+        {
+            "bluejay-ws",
+            "BLUEJAY-WS",
+            "bluejay-ws.iamworkin.lan",
+            "iamworkin-ws",
+        };
+
+        bool ContainsForbidden(string? value) =>
+            !string.IsNullOrWhiteSpace(value)
+            && forbiddenHostPatterns.Any(pattern => value!.Contains(pattern, StringComparison.OrdinalIgnoreCase));
+
+        var violations = GitHubRunnerDeployments().Values.SelectMany(deployment =>
+        {
+            var local = new List<string>();
+            var podSpec = ManifestNodeExtensions.Mapping(deployment.Root, "spec", "template", "spec");
+            if (podSpec is null)
+            {
+                return local;
+            }
+
+            // nodeName: pins the pod to a specific node by name.
+            var nodeName = ManifestNodeExtensions.Scalar(podSpec, "nodeName");
+            if (ContainsForbidden(nodeName))
+            {
+                local.Add($"{deployment.Name} sets nodeName='{nodeName}' which targets a forbidden operator-workstation host.");
+            }
+
+            // nodeSelector: dict of label → value pinning the pod to nodes
+            // carrying matching labels. Examples that would trip this:
+            //   kubernetes.io/hostname: bluejay-ws
+            //   flowercore.io/host: bluejay-ws.iamworkin.lan
+            var nodeSelector = ManifestNodeExtensions.Mapping(podSpec, "nodeSelector");
+            if (nodeSelector is not null)
+            {
+                foreach (var entry in nodeSelector.Children)
+                {
+                    var key = entry.Key is YamlScalarNode keyScalar ? keyScalar.Value : null;
+                    var value = entry.Value is YamlScalarNode valueScalar ? valueScalar.Value : null;
+                    if (ContainsForbidden(value))
+                    {
+                        local.Add($"{deployment.Name} has nodeSelector entry '{key}: {value}' which targets a forbidden operator-workstation host.");
+                    }
+                }
+            }
+
+            // nodeAffinity: matchExpressions over node labels.
+            foreach (var term in ManifestNodeExtensions.MappingSequence(podSpec, "affinity", "nodeAffinity", "requiredDuringSchedulingIgnoredDuringExecution", "nodeSelectorTerms"))
+            {
+                foreach (var expr in ManifestNodeExtensions.MappingSequence(term, "matchExpressions"))
+                {
+                    var key = ManifestNodeExtensions.Scalar(expr, "key");
+                    foreach (var valueNode in ManifestNodeExtensions.ScalarSequence(expr, "values"))
+                    {
+                        if (ContainsForbidden(valueNode))
+                        {
+                            local.Add($"{deployment.Name} has nodeAffinity matchExpression '{key}' value '{valueNode}' which targets a forbidden operator-workstation host.");
+                        }
+                    }
+                }
+            }
+
+            // tolerations: scheduling onto a tainted operator-workstation
+            // node would let the runner run there. Forbid any toleration
+            // value that names the workstation.
+            foreach (var toleration in ManifestNodeExtensions.MappingSequence(podSpec, "tolerations"))
+            {
+                var key = ManifestNodeExtensions.Scalar(toleration, "key");
+                var value = ManifestNodeExtensions.Scalar(toleration, "value");
+                if (ContainsForbidden(key))
+                {
+                    local.Add($"{deployment.Name} has toleration key '{key}' which targets a forbidden operator-workstation host.");
+                }
+                if (ContainsForbidden(value))
+                {
+                    local.Add($"{deployment.Name} has toleration value '{value}' which targets a forbidden operator-workstation host.");
+                }
+            }
+
+            return local;
+        }).ToList();
+
+        violations.Should().BeEmpty("BLUEJAY-WS / iamworkin-ws must never host a fleet GitHub Actions runner; see CLAUDE.md 'Registering BLUEJAY-WS as a fleet GitHub Actions runner' and feedback_bluejay_ws_never_public_runner.md");
+    }
+
     [Fact]
     public void Monitoring_MustAlertWhenLinuxRunnerDeploymentIsUnavailable()
     {
@@ -892,6 +997,22 @@ internal sealed record ManifestDocument(
             .ToList();
     }
 
+    // MainContainerMappings excludes initContainers. Use this when asserting
+    // properties of the primary container (env, image, volumeMounts) where an
+    // initContainer would be a false-positive match — e.g. the GitHub runner
+    // image's `setup-runner-home` initContainer should not count toward the
+    // single-container assertions on the runner deployments.
+    public IReadOnlyList<YamlMappingNode> MainContainerMappings()
+    {
+        var podSpec = PodSpec();
+        if (podSpec is null)
+        {
+            return Array.Empty<YamlMappingNode>();
+        }
+
+        return ManifestNodeExtensions.MappingSequence(podSpec, "containers").ToList();
+    }
+
     public IReadOnlyList<ContainerSpec> ContainerSpecs()
     {
         return ContainerMappings()