feat(v0.1): runner Job 直接挂载 per-session PVC + env 透传

PR C 起步：k8s-job.ts 加 sessionPvc volume + env passthrough

- src/runner/k8s-job.ts: 新 RunnerSessionPvcOptions 接口；manifest 多渲染
  agentrun-sessions volume + volumeMount；env 多透传 AGENTRUN_SESSION_PVC_NAME /
  _NAMESPACE / _MOUNT_PATH / AGENTRUN_CODEX_ROLLOUT_SUBDIR
- src/mgr/kubernetes-runner-job.ts: run 引用 session 时查 session storage
  kind=pvc 自动构造 sessionPvc 透传给 manifest 渲染；kind=evicted 已在
  PR B 短路返回 session-store-evicted
- selftest: 1 新 case runner-k8s-job-session-pvc-volume-and-env 验证 PVC volume
  + env 全套透传

后续 PR C 剩余：src/backend/codex-stdio.ts emit codex-rollout-storage-mounted
事件 + session-store-evicted 升级；3 个 codex-stdio 端到端 case。

src/runner/k8s-job.ts

@@ -19,9 +19,17 @@ export interface RunnerJobRenderOptions {
   backoffLimit?: number;
   ttlSecondsAfterFinished?: number;
   transientEnv?: RunnerTransientEnv[];
+  sessionPvc?: RunnerSessionPvcOptions;
   dryRun?: boolean;
 }
 
+export interface RunnerSessionPvcOptions {
+  pvcName: string;
+  namespace: string;
+  mountPath: string;
+  codexRolloutSubdir: string;
+}
+
 export interface RunnerTransientEnv {
   name: string;
   value: string;
@@ -91,9 +99,10 @@ export function renderRunnerJobManifest(options: RunnerJobRenderOptions): { mani
   const jobName = `agentrun-v01-runner-${shortDnsHash(options.run.id, attemptId)}`;
   const secretRefs = credentialProjections(options.run, namespace);
   const toolCredentials = toolCredentialProjections(options.run, namespace);
+  const sessionPvc = options.sessionPvc;
   const warnings: string[] = [];
   if (secretRefs.length === 0) warnings.push("run executionPolicy.secretScope 未声明 provider SecretRef；runner 将按 secret-unavailable 上报，而不会降级直连外部凭据");
-  const env = runnerEnv(options, { namespace, jobName, runnerId, attemptId, sourceCommit, secretRefs, toolCredentials });
+  const env = runnerEnv(options, { namespace, jobName, runnerId, attemptId, sourceCommit, secretRefs, toolCredentials, sessionPvc });
   const manifest: JsonRecord = {
     apiVersion: "batch/v1",
     kind: "Job",
@@ -132,6 +141,7 @@ export function renderRunnerJobManifest(options: RunnerJobRenderOptions): { mani
               volumeMounts: [
                 { name: "runner-home", mountPath: "/home/agentrun" },
                 ...secretRefs.map((item) => ({ name: item.volumeName, mountPath: item.projectionMountPath, readOnly: true })),
+                ...(sessionPvc ? [{ name: "agentrun-sessions", mountPath: sessionPvc.mountPath, readOnly: false }] : []),
               ],
               resources: {
                 requests: { cpu: "250m", memory: "512Mi" },
@@ -144,7 +154,11 @@ export function renderRunnerJobManifest(options: RunnerJobRenderOptions): { mani
               },
             },
           ],
-          volumes: [{ name: "runner-home", emptyDir: {} }, ...secretRefs.map(secretVolume)],
+          volumes: [
+            { name: "runner-home", emptyDir: {} },
+            ...secretRefs.map(secretVolume),
+            ...(sessionPvc ? [{ name: "agentrun-sessions", persistentVolumeClaim: { claimName: sessionPvc.pvcName } }] : []),
+          ],
         },
       },
     },
@@ -152,7 +166,7 @@ export function renderRunnerJobManifest(options: RunnerJobRenderOptions): { mani
   return { manifest, namespace, jobName, runnerId, attemptId, sourceCommit, serviceAccountName, secretRefs, toolCredentials, warnings, ttlSecondsAfterFinished };
 }
 
-function runnerEnv(options: RunnerJobRenderOptions, context: { namespace: string; jobName: string; runnerId: string; attemptId: string; sourceCommit: string; secretRefs: CredentialProjection[]; toolCredentials: ToolCredentialProjection[] }): JsonRecord[] {
+function runnerEnv(options: RunnerJobRenderOptions, context: { namespace: string; jobName: string; runnerId: string; attemptId: string; sourceCommit: string; secretRefs: CredentialProjection[]; toolCredentials: ToolCredentialProjection[]; sessionPvc: RunnerSessionPvcOptions | undefined }): JsonRecord[] {
   const selectedSecret = context.secretRefs.find((item) => item.profile === options.run.backendProfile);
   const codexHome = selectedSecret?.runtimeMountPath ?? defaultRuntimeHome(options.run.backendProfile);
   return [
@@ -180,6 +194,12 @@ function runnerEnv(options: RunnerJobRenderOptions, context: { namespace: string
     { name: "HOME", value: "/home/agentrun" },
     { name: "CODEX_HOME", value: codexHome },
     ...(selectedSecret ? [{ name: "AGENTRUN_CODEX_SECRET_HOME", value: selectedSecret.projectionMountPath }] : []),
+    ...(context.sessionPvc ? [
+      { name: "AGENTRUN_SESSION_PVC_NAME", value: context.sessionPvc.pvcName },
+      { name: "AGENTRUN_SESSION_PVC_NAMESPACE", value: context.sessionPvc.namespace },
+      { name: "AGENTRUN_SESSION_PVC_MOUNT_PATH", value: context.sessionPvc.mountPath },
+      { name: "AGENTRUN_CODEX_ROLLOUT_SUBDIR", value: context.sessionPvc.codexRolloutSubdir },
+    ] : []),
     ...toolCredentialEnvVars(context.toolCredentials),
     ...transientEnvVars(options.transientEnv ?? []),
   ];