fix: retry config snapshot after rejection (#83944)

Summary:
- This PR clears the cached CLI config snapshot promise when a read rejects, adds a reject-retry-cache regression test, and adds an Unreleased changelog entry.
- Reproducibility: yes. Current main clearly caches the first snapshot-read promise, and the source PR supplied a focused reject, recover, cached-success probe; I did not rerun it in this read-only review.

Automerge notes:
- PR branch already contained follow-up commit before automerge: fix: retry config snapshot after rejection

Validation:
- ClawSweeper review passed for head a46b5ec5c7.
- Required merge gates passed before the squash merge.

Prepared head SHA: a46b5ec5c7
Review: https://github.com/openclaw/openclaw/pull/83944#issuecomment-4484051060

Co-authored-by: honor2030 <19909783+honor2030@users.noreply.github.com>
Co-authored-by: clawsweeper <274271284+clawsweeper[bot]@users.noreply.github.com>
Co-authored-by: clawsweeper[bot] <274271284+clawsweeper[bot]@users.noreply.github.com>
Approved-by: takhoffman
Co-authored-by: takhoffman <781889+takhoffman@users.noreply.github.com>

src/cli/program/config-guard.test.ts

@@ -130,6 +130,31 @@ describe("ensureConfigReady", () => {
     );
   });
 
+  it("retries the cached config snapshot after a read rejection", async () => {
+    const originalVitest = process.env.VITEST;
+    process.env.VITEST = "false";
+    const transientError = new Error("temporary config read failure");
+    const recoveredSnapshot = makeSnapshot();
+    readConfigFileSnapshotMock
+      .mockRejectedValueOnce(transientError)
+      .mockResolvedValueOnce(recoveredSnapshot);
+
+    try {
+      await expect(runEnsureConfigReady(["status"])).rejects.toThrow(transientError);
+      await expect(runEnsureConfigReady(["status"])).resolves.toBeDefined();
+      await expect(runEnsureConfigReady(["status"])).resolves.toBeDefined();
+    } finally {
+      if (originalVitest === undefined) {
+        delete process.env.VITEST;
+      } else {
+        process.env.VITEST = originalVitest;
+      }
+    }
+
+    expect(readConfigFileSnapshotMock).toHaveBeenCalledTimes(2);
+    expect(setRuntimeConfigSnapshotMock).toHaveBeenCalledWith(undefined, undefined);
+  });
+
   it("exits for invalid config on non-allowlisted commands", async () => {
     setInvalidSnapshot();
     const runtime = await runEnsureConfigReady(["message"]);

src/cli/program/config-guard.ts

@@ -30,7 +30,15 @@ async function getConfigSnapshot() {
   if (process.env.VITEST === "true") {
     return readConfigFileSnapshot();
   }
-  configSnapshotPromise ??= readConfigFileSnapshot();
+  if (!configSnapshotPromise) {
+    const pendingSnapshot = readConfigFileSnapshot();
+    configSnapshotPromise = pendingSnapshot;
+    pendingSnapshot.catch(() => {
+      if (configSnapshotPromise === pendingSnapshot) {
+        configSnapshotPromise = null;
+      }
+    });
+  }
   return configSnapshotPromise;
 }