test(#1971): isolate folded CLI blocks from host ambient GSD_ env

gsd-test surfaced 9 failures: folded fix-1437 (phase.list-plans) and bug-1826
(phases clear) tests spawn gsd-tools via runGsdTools, which copies process.env into
the child. Their host suites (phase-command-router / phases-command-router) force
GSD_WORKSTREAM=test-unit at the suite level, redirecting the child's project lookup
away from each test's temp project → plan/dir counts came back 0. Clear GSD_WORKSTREAM
in each folded block's beforeEach (restoring the standalone condition) and restore in
afterEach. Also scope the folded bug-416 GSD_TEST_MODE set to a before/after hook in
health-validation (Codex review) so it no longer leaks into host child processes.
Assertions unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/health-validation.test.cjs

@@ -722,8 +722,6 @@ describe('Drift item 3 — W006 false positive when disk has zero-padded letter
  * Answer space: <dir> | null.
  */
 
-process.env.GSD_TEST_MODE = '1';
-
 const { describe, test, before, after } = require('node:test');
 const assert = require('node:assert/strict');
 const fs = require('node:fs');
@@ -732,6 +730,15 @@ const os = require('node:os');
 
 const { runGsdTools, cleanup } = require('./helpers.cjs');
 
+// Consolidation #1969: scope GSD_TEST_MODE to this folded block so it does not
+// leak (via the runGsdTools env copy) into host tests registered before the fold.
+const __savedTestMode = process.env.GSD_TEST_MODE;
+before(() => { process.env.GSD_TEST_MODE = '1'; });
+after(() => {
+  if (__savedTestMode === undefined) delete process.env.GSD_TEST_MODE;
+  else process.env.GSD_TEST_MODE = __savedTestMode;
+});
+
 // ── helpers ──────────────────────────────────────────────────────────────────
 
 function mkplanning(base) {

tests/phase-command-router.test.cjs

@@ -481,8 +481,14 @@ function touch(dir, ...files) {
 
 let tmpDir;
 let phaseDir;
+// Consolidation #1969: the host suite forces GSD_WORKSTREAM=test-unit, which
+// runGsdTools propagates into child processes and redirects the project lookup.
+// Clear it for these tests (unset when this file ran standalone); restore after.
+let __savedWorkstream;
 
 beforeEach(() => {
+  __savedWorkstream = process.env.GSD_WORKSTREAM;
+  delete process.env.GSD_WORKSTREAM;
   const proj = setupProject('01-feature');
   tmpDir = proj.tmpDir;
   phaseDir = proj.phaseDir;
@@ -490,6 +496,8 @@ beforeEach(() => {
 
 afterEach(() => {
   cleanup(tmpDir);
+  if (__savedWorkstream === undefined) delete process.env.GSD_WORKSTREAM;
+  else process.env.GSD_WORKSTREAM = __savedWorkstream;
 });
 
 describe('bug-1437 — phase.list-plans is wired in gsd-tools', () => {

tests/phases-command-router.test.cjs

@@ -114,13 +114,21 @@ const { runGsdTools, createTempProject, cleanup } = require('./helpers.cjs');
 
 describe('bug #1826: phases clear --confirm guard', () => {
   let tmpDir;
+  // Consolidation #1969: the host suite forces GSD_WORKSTREAM=test-unit, which
+  // runGsdTools propagates into child processes and redirects the project lookup.
+  // Clear it for these tests (unset when this file ran standalone); restore after.
+  let __savedWorkstream;
 
   beforeEach(() => {
+    __savedWorkstream = process.env.GSD_WORKSTREAM;
+    delete process.env.GSD_WORKSTREAM;
     tmpDir = createTempProject();
   });
 
   afterEach(() => {
     cleanup(tmpDir);
+    if (__savedWorkstream === undefined) delete process.env.GSD_WORKSTREAM;
+    else process.env.GSD_WORKSTREAM = __savedWorkstream;
   });
 
   test('phases clear without --confirm is rejected when phase dirs exist', () => {