fix: make global-install-smoke work under GHA CI skip

Isolated smoke now forces postinstall and clears CI env vars so five host receipts are written when GITHUB_ACTIONS is set. Lifecycle tests cover CI+global no-op versus FORCE execute so local green cannot hide the GHA failure mode.

Author: rockyshi1993

scripts/lib/npm-lifecycle-adapter.js

@@ -110,6 +110,9 @@ function classifyNpmLifecycleInstall(options = {}) {
   if (!isPostinstall) return noOp('not-postinstall')
   if (truthy(env.DEVCODEX_SKIP_POSTINSTALL)) return noOp('skip-env')
   if (truthy(env.DEVCODEX_POSTINSTALL_CHILD)) return noOp('child-process')
+  // CI skip is intentional for workspace/CI jobs so runners do not mutate host homes.
+  // Real global install on CI is also skipped unless DEVCODEX_POSTINSTALL_FORCE=1
+  // (global-install-smoke must set force + clear CI vars in its isolated env).
   if (!force && ci) return noOp('ci')
   if (globalInstall) {
     return {

scripts/test-global-install-smoke.js

@@ -71,8 +71,15 @@ function runCommand(command, args, options = {}) {
 }
 
 function isolatedHostEnv(home) {
+  // Global postinstall skips when CI/GITHUB_ACTIONS is truthy (see npm-lifecycle-adapter).
+  // Smoke inherits process.env from GHA; force + clear CI vars so isolated receipts are written.
   return {
     DEVCODEX_TEST_HOME: home,
+    DEVCODEX_POSTINSTALL_FORCE: '1',
+    CI: '',
+    GITHUB_ACTIONS: '',
+    BUILDKITE: '',
+    TF_BUILD: '',
     CODEX_HOME: path.join(home, '.codex'),
     CLAUDE_CONFIG_DIR: path.join(home, '.claude'),
     GEMINI_CLI_HOME: path.join(home, 'gemini-cli-home'),

scripts/test-npm-lifecycle-adapter.js

@@ -193,6 +193,34 @@ assert.strictEqual(classify({ DEVCODEX_SKIP_POSTINSTALL: '1' }).reason, 'skip-en
 assert.strictEqual(classify({ DEVCODEX_POSTINSTALL_CHILD: '1' }).reason, 'child-process')
 assert.strictEqual(classify({}, transitiveWorkspace).reason, 'transitive-or-indirect')
 
+// CI skip runs before globalInstall (S-a): real GHA postinstall stays no-op unless forced.
+// Prevents global-install-smoke from going green locally while red under GITHUB_ACTIONS.
+const ciGlobalDecision = classify({ CI: 'true', npm_config_global: 'true', INIT_CWD: workspace })
+assert.strictEqual(ciGlobalDecision.action, 'noop')
+assert.strictEqual(ciGlobalDecision.reason, 'ci')
+assert.strictEqual(ciGlobalDecision.globalInstall, true)
+const ghaGlobalDecision = classify({ GITHUB_ACTIONS: 'true', npm_config_global: 'true', INIT_CWD: workspace })
+assert.strictEqual(ghaGlobalDecision.action, 'noop')
+assert.strictEqual(ghaGlobalDecision.reason, 'ci')
+const ciGlobalWithTestHome = classify({
+  CI: 'true',
+  npm_config_global: 'true',
+  DEVCODEX_TEST_HOME: path.join(tmp, 'isolated-home'),
+  INIT_CWD: workspace
+})
+assert.strictEqual(ciGlobalWithTestHome.action, 'noop', 'DEVCODEX_TEST_HOME alone must not bypass CI skip')
+assert.strictEqual(ciGlobalWithTestHome.reason, 'ci')
+const ciGlobalForced = classify({
+  CI: 'true',
+  GITHUB_ACTIONS: 'true',
+  npm_config_global: 'true',
+  DEVCODEX_POSTINSTALL_FORCE: '1',
+  INIT_CWD: workspace
+})
+assert.strictEqual(ciGlobalForced.action, 'execute')
+assert.strictEqual(ciGlobalForced.reason, 'global-install-postinstall')
+assert.strictEqual(ciGlobalForced.scope, 'global-install')
+
 const sourceGlobalDecision = classify({ npm_config_global: 'true', INIT_CWD: workspace }, workspace, sourceRoot)
 assert.strictEqual(sourceGlobalDecision.action, 'execute')
 assert.strictEqual(sourceGlobalDecision.scope, 'global-install')