Preserve runner process start time across controller recovery

Use the verified remote process marker and adopted process identity when reporting runner process metadata, rather than the creation time of a replacement controller transport.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/paperclip-runner/src/live/runnerd-codex-transport.test.ts

@@ -3212,7 +3212,7 @@ async function verifyLiveRunnerAdoption(mismatchedCheckpoint: boolean) {
       adoptExistingRunner: {
         pid: runnerPid!,
         processGroupId: runnerPid,
-        startedAt: new Date().toISOString(),
+        startedAt: "2026-09-01T10:00:00.000Z",
         isAlive: () => {
           try {
             process.kill(runnerPid!, 0);
@@ -3237,6 +3237,7 @@ async function verifyLiveRunnerAdoption(mismatchedCheckpoint: boolean) {
       }),
     );
     expect(adopted.evidence().runnerPid).toBe(runnerPid);
+    expect(adopted.transport.processInfo?.().startedAt).toBe("2026-09-01T10:00:00.000Z");
     expect(duplicateLauncher).not.toHaveBeenCalled();
     expect(adopted.evidence().diagnostics).toContain(
       `adopted runner ${runnerPid} authenticated to its durable PRP authority`,

packages/paperclip-runner/src/live/runnerd-codex-transport.ts

@@ -2515,7 +2515,8 @@ class DurablePrpCodexTransport implements CodexAppServerTransport {
     return {
       pid: this.#evidence.runnerPid,
       processGroupId: this.#evidence.runnerProcessGroupId,
-      startedAt: this.#startedAt,
+      // Reconnecting creates a new transport, not a new runner process.
+      startedAt: this.options.adoptExistingRunner?.startedAt ?? this.#handle?.startedAt ?? this.#startedAt,
       exited: this.#evidence.runnerExited,
       exitCode: this.#evidence.runnerExitCode,
       signal: this.#evidence.runnerSignal,

server/src/services/native-runtime/native-session-executor.test.ts

@@ -341,6 +341,7 @@ describe("remote runner process supervision", () => {
       startedAt: "2026-09-06T00:00:00.000Z",
     });
     expect(handle.child.pid).toBe(4321);
+    expect(handle.startedAt).toBe("2026-09-06T00:00:00.000Z");
 
     expect(handle.child.kill("SIGKILL")).toBe(true);
     await vi.waitFor(() =>

server/src/services/native-runtime/native-session-executor.ts

@@ -6362,7 +6362,11 @@ export function createRemoteRunnerProcessLauncher(input: {
         };
       }
     })();
-    return { child, completion };
+    return {
+      child,
+      completion,
+      get startedAt() { return launchedIdentity?.startedAt; },
+    };
   };
 }