perf(ci): share bytecode across fresh Apple artifact subprocesses

.github/workflows/ci.yml

@@ -378,6 +378,8 @@ jobs:
           cache: npm
       - run: npm ci
       - name: Verify Apple artifact formats and metadata
+        env:
+          REA_ARTIFACT_NODE_COMPILE_CACHE: ${{ runner.temp }}/rea-artifact-node-cache
         run: |
           npm run verify:keyed-archive
           npm run verify:asset-catalog

docs/testing.md

@@ -991,6 +991,13 @@ the fixture cache. These subprocesses are outside aggregate Vitest coverage;
 subprocess coverage attachment remains disabled. Cold-start import checks launch
 independently without this fixture cache.
 
+The Apple artifact verifier step shares a job-temporary bytecode cache among
+its fresh CLI/MCP children via `REA_ARTIFACT_NODE_COMPILE_CACHE`. The artifact
+helper maps this setting to child `NODE_COMPILE_CACHE`; npm, Turbo, and nested
+Vitest runs do not inherit that setting. Explicit `NODE_COMPILE_CACHE` takes
+precedence, and coverage collection or `NODE_DISABLE_COMPILE_CACHE=1` disables
+the helper's cache. The cache is discarded with the CI job.
+
 To evaluate persistent compile caching for repeated local runs, opt in for both
 cold and warm measurements with an isolated cache:
 

scripts/lib/artifact-e2e.mjs

@@ -5,13 +5,23 @@ import { fileURLToPath } from "node:url";
 import { Client } from "@modelcontextprotocol/client";
 import { StdioClientTransport } from "@modelcontextprotocol/client/stdio";
 
-const environment = () => ({
-  PATH: process.env.PATH ?? "/usr/bin:/bin",
-  REA_LOG_LEVEL: "silent",
-  REA_ANALYSIS_PROVIDER: "auto",
-  // Artifact workflows have no deep-provider prerequisite or GUI authority.
-  HOPPER_LAUNCHER_PATH: "/rea-unconfigured-deep-provider/hopper",
-});
+const environment = () => {
+  const compileCache =
+    process.env.NODE_COMPILE_CACHE ??
+    process.env.REA_ARTIFACT_NODE_COMPILE_CACHE;
+  return {
+    PATH: process.env.PATH ?? "/usr/bin:/bin",
+    ...(compileCache &&
+    process.env.NODE_V8_COVERAGE === undefined &&
+    process.env.NODE_DISABLE_COMPILE_CACHE !== "1"
+      ? { NODE_COMPILE_CACHE: compileCache }
+      : {}),
+    REA_LOG_LEVEL: "silent",
+    REA_ANALYSIS_PROVIDER: "auto",
+    // Artifact workflows have no deep-provider prerequisite or GUI authority.
+    HOPPER_LAUNCHER_PATH: "/rea-unconfigured-deep-provider/hopper",
+  };
+};
 
 /** Execute the compiled CLI with production providers and no test adapters. */
 export async function artifactCli(