test(gateway): give module-mocking Gateway tests a private module graph

`server.sessions.compaction-read-errors` mocks
`config/sessions/session-accessor.sqlite-read.js`, but production reaches
`loadTranscriptEvents` through re-exports: `server-methods/sessions-compact.ts`
imports it from the `session-accessor.js` barrel and
`preflightSessionTranscriptForManualCompact` imports it from the leaf. The
`gateway-server` project is `isolate: false`, so when a neighbour has already
evaluated those importers they stay bound to the real implementation and the
mock never fires -- the injected read error simply does not happen and all three
tests fail with `expected true to be false`, reading like a product regression.

Trigger: 33744584f3 added `server.chat-metadata-boundary.test.ts`, which boots
a full non-minimal Gateway in `beforeAll` and lands immediately before this file
in the shard. Main has gone red on it repeatedly since (32338154086, 32339521003,
32339928383, 32341300955, 32341946296); e294c154a6 fixed only the sibling
symptom where the factory had not run yet.

Route the file to a new `gateway-server-isolated` project instead, mirroring
`unit-fast-isolated` -- whose comment describes this exact hazard. A fresh graph
per file makes both symptoms structurally impossible rather than order-dependent.
The list is explicit so the reason travels with the file.

Not reproducible on macOS: the exact 24-file stripe in CI's own order, and the
triggering pair three times, are green locally every time.

scripts/lib/ci-node-test-plan.mts

@@ -7,6 +7,7 @@ import {
 import { commandsLightTestFiles } from "../../test/vitest/vitest.commands-light-paths.mjs";
 import {
   gatewayServerExcludedTestFiles,
+  gatewayServerIsolatedTestFiles,
   isGatewayServerBackedHttpTestFile,
   isGatewayServerTestFile,
 } from "../../test/vitest/vitest.gateway-server-paths.mjs";
@@ -264,6 +265,8 @@ const COMPACT_GROUP_SECONDS_HINTS = new Map<string, number>([
   ["agentic-gateway-core-1", 99],
   ["agentic-gateway-core-2", 99],
   ["agentic-gateway-core-3", 99],
+  // One small file that pays a full cold module graph because it runs isolated.
+  ["agentic-gateway-server-isolated", 30],
   ["agentic-gateway-methods", 157],
   ["agentic-plugin-sdk", 45],
   ["auto-reply-core-top-level", 27],
@@ -1637,7 +1640,10 @@ function createCoreRuntimeMediaUiSplitShards(): NodeTestSplitShard[] {
 
 function createAgenticGatewayCoreSplitShards(): NodeTestSplitShard[] {
   const unitFastFiles = new Set(getUnitFastTestFiles());
-  const excludedGatewayFiles = new Set(gatewayServerExcludedTestFiles);
+  const excludedGatewayFiles = new Set([
+    ...gatewayServerExcludedTestFiles,
+    ...gatewayServerIsolatedTestFiles,
+  ]);
   const gatewayFiles = listTestFiles("src/gateway").filter(
     (file) =>
       isStripeEligibleTestFile(file, unitFastFiles) &&
@@ -1747,6 +1753,11 @@ const SPLIT_NODE_SHARDS = new Map<string, NodeTestSplitShard[]>([
     "agentic",
     [
       ...createGatewayServerSplitShards(),
+      {
+        shardName: "agentic-gateway-server-isolated",
+        configs: ["test/vitest/vitest.gateway-server-isolated.config.ts"],
+        requiresDist: false,
+      },
       // Split per config: the combined pair owned a ~206s hosted wall that no
       // bin packing could shorten, while the halves fit normal lanes.
       {

test/scripts/ci-node-test-plan.test.ts

@@ -318,27 +318,27 @@ describe("scripts/lib/ci-node-test-plan.mts", () => {
         name: "Blacksmith",
         pullRequest: pullRequestCompact,
         pullRequestJobs: 34,
-        pullRequestMax: 204,
+        pullRequestMax: 207,
         push: compact,
         pushJobs: 25,
-        pushMax: 204,
+        pushMax: 207,
       },
       {
         name: "GitHub-hosted",
         pullRequest: githubPullRequestCompact,
-        pullRequestJobs: 79,
+        pullRequestJobs: 80,
         pullRequestMax: 186,
         push: githubCompact,
-        pushJobs: 70,
+        pushJobs: 71,
         pushMax: 149,
       },
       {
         name: "hybrid",
         pullRequest: hybridPullRequestCompact,
-        pullRequestJobs: 56,
+        pullRequestJobs: 57,
         pullRequestMax: 140,
         push: hybridCompact,
-        pushJobs: 48,
+        pushJobs: 49,
         pushMax: 140,
       },
     ]) {
@@ -355,7 +355,7 @@ describe("scripts/lib/ci-node-test-plan.mts", () => {
         `${profile.name} pull-request max`,
       ).toBe(profile.pullRequestMax);
     }
-    expect(hybridCompact.filter((shard) => !shard.requiresDist)).toHaveLength(47);
+    expect(hybridCompact.filter((shard) => !shard.requiresDist)).toHaveLength(48);
     expect(githubCompact.length - hybridCompact.length).toBeGreaterThanOrEqual(20);
     expect(githubPullRequestCompact.length).toBeLessThanOrEqual(96);
     // Nondist expanded-profile lanes stay under the 150-second body ceiling;

test/vitest/vitest.gateway-server-isolated.config.ts

@@ -0,0 +1,33 @@
+// Vitest gateway server isolated config wires module-mocking Gateway tests out of
+// the shared module cache.
+import { defineConfig } from "vitest/config";
+import { gatewayServerIsolatedTestFiles } from "./vitest.gateway-server-paths.mjs";
+import { loadPatternListFromEnv, narrowIncludePatternsForCli } from "./vitest.pattern-file.ts";
+import { resolveRepoRootPath, sharedVitestConfig } from "./vitest.shared.config.ts";
+
+export function createGatewayServerIsolatedVitestConfig(
+  env: Record<string, string | undefined> = process.env,
+  options: { argv?: string[] } = {},
+) {
+  const sharedTest = sharedVitestConfig.test ?? {};
+  const includeFromEnv = loadPatternListFromEnv("OPENCLAW_VITEST_INCLUDE_FILE", env);
+  const cliInclude = narrowIncludePatternsForCli(gatewayServerIsolatedTestFiles, options.argv);
+
+  return defineConfig({
+    ...sharedVitestConfig,
+    test: {
+      ...sharedTest,
+      name: "gateway-server-isolated",
+      // These files replace a module the Gateway reaches through re-exports, so a
+      // neighbour that already bound the real implementation would defeat the mock.
+      isolate: true,
+      runner: undefined,
+      setupFiles: [resolveRepoRootPath("test/setup.env.ts")],
+      include: includeFromEnv ?? cliInclude ?? gatewayServerIsolatedTestFiles,
+      exclude: sharedTest.exclude ?? [],
+      passWithNoTests: true,
+    },
+  });
+}
+
+export default createGatewayServerIsolatedVitestConfig();

test/vitest/vitest.gateway-server-paths.d.mts

@@ -1,4 +1,5 @@
 export const gatewayServerBackedHttpTestFiles: string[];
 export const gatewayServerExcludedTestFiles: string[];
+export const gatewayServerIsolatedTestFiles: string[];
 export function isGatewayServerBackedHttpTestFile(file: string): boolean;
 export function isGatewayServerTestFile(file: string): boolean;

test/vitest/vitest.gateway-server-paths.mjs

@@ -7,6 +7,15 @@ export const gatewayServerBackedHttpTestFiles = [
   "src/gateway/probe.auth.integration.test.ts",
 ];
 
+// Gateway server tests that replace a module the Gateway reaches only through
+// re-exports. `gateway-server` is `isolate: false`, so a neighbour that boots a
+// full Gateway leaves those importers bound to the real implementation and the
+// mock silently never fires. These run in `gateway-server-isolated` instead,
+// which gives each file a fresh module graph.
+export const gatewayServerIsolatedTestFiles = [
+  "src/gateway/server.sessions.compaction-read-errors.test.ts",
+];
+
 export const gatewayServerExcludedTestFiles = [
   "src/gateway/gateway.test.ts",
   "src/gateway/server.startup-matrix-migration.integration.test.ts",
@@ -15,6 +24,7 @@ export const gatewayServerExcludedTestFiles = [
 
 const gatewayServerBackedHttpTestFileSet = new Set(gatewayServerBackedHttpTestFiles);
 const gatewayServerExcludedTestFileSet = new Set(gatewayServerExcludedTestFiles);
+const gatewayServerIsolatedTestFileSet = new Set(gatewayServerIsolatedTestFiles);
 
 export function isGatewayServerBackedHttpTestFile(file) {
   return gatewayServerBackedHttpTestFileSet.has(file.replaceAll("\\", "/"));
@@ -24,6 +34,7 @@ export function isGatewayServerTestFile(file) {
   const normalized = file.replaceAll("\\", "/");
   if (
     gatewayServerExcludedTestFileSet.has(normalized) ||
+    gatewayServerIsolatedTestFileSet.has(normalized) ||
     normalized.startsWith("src/gateway/server-methods/") ||
     normalized.endsWith(".e2e.test.ts")
   ) {

test/vitest/vitest.gateway-server.config.ts

@@ -1,6 +1,7 @@
 import {
   gatewayServerBackedHttpTestFiles,
   gatewayServerExcludedTestFiles,
+  gatewayServerIsolatedTestFiles,
 } from "./vitest.gateway-server-paths.mjs";
 // Vitest gateway server config wires the gateway server test shard.
 import { createScopedVitestConfig } from "./vitest.scoped-config.ts";
@@ -11,7 +12,11 @@ export function createGatewayServerVitestConfig(env?: Record<string, string | un
     {
       dir: "src/gateway",
       env,
-      exclude: ["src/gateway/server-methods/**/*.test.ts", ...gatewayServerExcludedTestFiles],
+      exclude: [
+        "src/gateway/server-methods/**/*.test.ts",
+        ...gatewayServerExcludedTestFiles,
+        ...gatewayServerIsolatedTestFiles,
+      ],
       fileParallelism: false,
       // Gateway child projects share one include file; preserve this project's ownership.
       intersectIncludeFile: true,

test/vitest/vitest.gateway.config.ts

@@ -7,6 +7,7 @@ const gatewayProjectConfigs = [
   "test/vitest/vitest.gateway-client.config.ts",
   "test/vitest/vitest.gateway-methods.config.ts",
   "test/vitest/vitest.gateway-server.config.ts",
+  "test/vitest/vitest.gateway-server-isolated.config.ts",
 ] as const;
 
 export function createGatewayVitestConfig(env?: Record<string, string | undefined>) {

test/vitest/vitest.test-shards.mjs

@@ -99,6 +99,7 @@ export const fullSuiteVitestShards = [
       "test/vitest/vitest.gateway-client.config.ts",
       "test/vitest/vitest.gateway-methods.config.ts",
       "test/vitest/vitest.gateway-server.config.ts",
+      "test/vitest/vitest.gateway-server-isolated.config.ts",
       "test/vitest/vitest.cli-process.config.ts",
       "test/vitest/vitest.cli.config.ts",
       "test/vitest/vitest.commands-light.config.ts",