fix(FN-6587): stabilize test lanes under production env

Normalize spawned Vitest processes to NODE_ENV=test so React/jsdom lanes do not inherit release-shell production mode. Split the compound-engineering plugin Vitest projects so Node-only setup and teardown only run in Node lanes, and quarantine the remaining broad-lane CE timeout flakes under the deletion ratchet.

packages/dashboard/vitest.config.ts

@@ -6,6 +6,12 @@ import { computeMaxWorkers } from "../core/src/__test-utils__/vitest-workers";
 
 const maxWorkers = computeMaxWorkers({ defaultCap: 3 });
 
+/*
+FNXC:DashboardTests 2026-06-17-17:02:
+Dashboard tests must be insulated from release-oriented shells that export NODE_ENV=production. Force test mode before Vitest resolves React and Testing Library so jsdom projects keep React.act and do not fail after slow browser-environment startup.
+*/
+process.env.NODE_ENV = "test";
+
 // Curated-gate skip-list (plan U2 / R7). Files listed here run in NO project on
 // purpose (pre-existing failures discovered when the curated-gate hole was
 // closed). The skip-list is the single source of truth shared with

plugins/fusion-plugin-compound-engineering/vitest.config.ts

@@ -4,6 +4,12 @@ import { computeMaxWorkers } from "../../packages/core/src/__test-utils__/vitest
 
 const maxWorkers = computeMaxWorkers();
 
+/*
+FNXC:CompoundEngineeringTests 2026-06-17-17:02:
+Direct CE plugin test commands must behave like the central pnpm test runner even when the caller's shell exports NODE_ENV=production. Force test mode before Vitest resolves React Testing Library so jsdom tests use React's act-capable test path.
+*/
+process.env.NODE_ENV = "test";
+
 const coreSetup = fileURLToPath(
   new URL("../../packages/core/src/__test-utils__/vitest-setup.ts", import.meta.url),
 );
@@ -12,10 +18,18 @@ const dashboardSetup = fileURLToPath(new URL("./src/dashboard/test-setup.ts", im
 /*
 FNXC:CompoundEngineeringTests 2026-06-17-12:35:
 FN-6587 quarantines the CE broad-pnpm-test timeout flakes without timeout appeasement. Keep these excludes mirrored in scripts/lib/test-quarantine.json and remove or delete the files when the 14-day ratchet resolves.
+
+FNXC:CompoundEngineeringTests 2026-06-17-17:18:
+The CE broad package lane still times out in sync/work-bridge hooks under project concurrency while both files pass in isolation. Quarantine the files under the deletion ratchet instead of raising hook timeouts or serializing the whole plugin lane.
 */
 const quarantinedCompoundEngineeringTests = [
   "src/__tests__/orchestrator-flow.test.ts",
   "src/__tests__/skill-wiring.test.ts",
+  "src/__tests__/sync.test.ts",
+  "src/__tests__/work-bridge.test.ts",
+];
+const nodeOnlyDashboardTests = [
+  "src/dashboard/__tests__/theme-tokens.test.ts",
 ];
 
 export default defineConfig({
@@ -42,8 +56,6 @@ export default defineConfig({
     ],
   },
   test: {
-    // coreSetup runs for all projects via extends: true inheritance.
-    setupFiles: [coreSetup],
     globalSetup: [fileURLToPath(new URL("../../packages/core/src/__test-utils__/vitest-teardown.ts", import.meta.url))],
     pool: "threads",
     maxWorkers,
@@ -55,7 +67,18 @@ export default defineConfig({
           name: "compound-engineering-dashboard",
           environment: "jsdom",
           include: ["src/dashboard/**/__tests__/**/*.test.{ts,tsx}", "src/dashboard/**/*.test.{ts,tsx}"],
-          // jsdom-specific setup; coreSetup is inherited via extends: true.
+          exclude: nodeOnlyDashboardTests,
+          globalSetup: [],
+          /*
+          FNXC:CompoundEngineeringTests 2026-06-17-16:50:
+          Dashboard tests run in jsdom and must not inherit the core Node-only isolation setup. That setup imports node:module/node:worker_threads and makes Vite externalize built-ins during browser-style setup, which regressed the CE test lane into slow startup followed by ERR_UNKNOWN_BUILTIN_MODULE.
+
+          FNXC:CompoundEngineeringTests 2026-06-17-16:54:
+          File-inspection dashboard tests that read CSS from disk are Node tests even though they live beside React tests. Keep them out of the jsdom project so fs/path/url imports are not browser-externalized.
+
+          FNXC:CompoundEngineeringTests 2026-06-17-17:10:
+          Projects that do not run the core isolation setup must not inherit its global teardown. Otherwise a completed dashboard project can remove FUSION_TEST_WORKER_ROOT while the CE Node project is still redirecting tmpdir writes there.
+          */
           setupFiles: [dashboardSetup],
         },
       },
@@ -65,6 +88,7 @@ export default defineConfig({
           name: "compound-engineering-node",
           environment: "node",
           include: ["src/**/__tests__/**/*.test.{ts,tsx}", "src/**/*.test.{ts,tsx}"],
+          setupFiles: [coreSetup],
           exclude: [
             "src/dashboard/**/__tests__/**/*.test.{ts,tsx}",
             "src/dashboard/**/*.test.{ts,tsx}",
@@ -72,6 +96,16 @@ export default defineConfig({
           ],
         },
       },
+      {
+        extends: true,
+        test: {
+          name: "compound-engineering-dashboard-node",
+          environment: "node",
+          include: nodeOnlyDashboardTests,
+          globalSetup: [],
+          setupFiles: [],
+        },
+      },
     ],
   },
 });

scripts/lib/test-quarantine.json

@@ -20,6 +20,16 @@
       "file": "plugins/fusion-plugin-compound-engineering/src/__tests__/skill-wiring.test.ts",
       "reason": "FN-6587 broad pnpm test investigation: this CE skill-wiring file was reported as timing out at Vitest's 5000ms test limit only in the broad pnpm test workflow; isolated two-file repro and loaded compound-engineering-node runs passed, and the broad command hit its external 900s workflow timeout before reproducing the named CE timeout. Quarantined per deletion-ratchet policy without timeout bumps, retries, or assertion loosening.",
       "quarantinedAt": "2026-06-17"
+    },
+    {
+      "file": "plugins/fusion-plugin-compound-engineering/src/__tests__/sync.test.ts",
+      "reason": "CE broad package verification under NODE_ENV=production fix hit a 10000ms beforeEach hook timeout only in the full @fusion-plugin-examples/compound-engineering lane, while an immediate isolated compound-engineering-node run of sync.test.ts passed in 15.43s. Quarantined per deletion-ratchet policy without hookTimeout increases, retries, or assertion loosening.",
+      "quarantinedAt": "2026-06-17"
+    },
+    {
+      "file": "plugins/fusion-plugin-compound-engineering/src/__tests__/work-bridge.test.ts",
+      "reason": "CE broad package verification under NODE_ENV=production fix hit a 10000ms beforeEach hook timeout only in the full @fusion-plugin-examples/compound-engineering lane, while an immediate isolated compound-engineering-node run of work-bridge.test.ts passed in 10.96s. Quarantined per deletion-ratchet policy without hookTimeout increases, retries, or assertion loosening.",
+      "quarantinedAt": "2026-06-17"
     }
   ]
 }

scripts/test-changed.mjs

@@ -1184,8 +1184,19 @@ export function createIsolatedHomeEnv(env = process.env) {
   return { env: nextEnv, isolatedHome };
 }
 
+export function createTestProcessEnv(env = process.env) {
+  /*
+  FNXC:TestInfrastructure 2026-06-17-17:02:
+  Developer shells and release scripts can export NODE_ENV=production, but Vitest must resolve React, Testing Library, and Vite transforms through their test/development paths. Normalize spawned test processes here so pnpm test cannot inherit production React test-utils and stall/fail jsdom lanes.
+  */
+  return {
+    ...env,
+    NODE_ENV: "test",
+  };
+}
+
 const fullSuiteEnv = {
-  ...process.env,
+  ...createTestProcessEnv(process.env),
   FUSION_TEST_TOTAL_WORKERS: process.env.FUSION_TEST_TOTAL_WORKERS || String(totalWorkers),
   FUSION_TEST_CONCURRENCY: process.env.FUSION_TEST_CONCURRENCY || String(concurrency),
 };