test: gate-tier E2E proving /ship dispatches the document-release subagent

New skill-e2e-ship-docsync: a live agent gets the sliced Step 17→19 tail
of the generated ship skeleton in a bare-remote git fixture (Steps 0-16
"done"), under a fake HOME so the STOP pointer and the Step 18 subagent
prompt resolve to planted copies, with a stub document-release skill that
returns the empty-result JSON contract. Hard assert: an Agent/Task
tool-call matching /document-release/i exists in result.toolCalls and
precedes any `gh pr create`. Neutral prompt (no STOP-Read priming, no
document-release mention — the prompt echoes into the transcript, so
asserts read toolCalls only).

Hardening from review: throw-on-marker-drift fixture slice; per-test
GSTACK_HOME + .redact-prepush-prompted marker (routes Step 17's
credential guard to its silent branch — the hermetic GSTACK_HOME pin
defeats a HOME-only override); 480s/540s timeouts (nested subagent adds
wall clock the 300s sibling never carried); 'timeout' accepted in
exitReason only because the dispatch assert is independently hard;
whole-file describeE2ETier('gate') composed with diff selection (keeps
the file out of the periodic shard census, which sits at its ceiling,
and under the hard tier-alignment invariant).

Registered as 'ship-docsync' in E2E_TOUCHFILES + E2E_TIERS (gate) in the
same commit — touchfiles.test.ts rejects either half landing first.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/helpers/touchfiles-data.ts

@@ -281,6 +281,7 @@ export const E2E_TOUCHFILES: Record<string, string[]> = {
   'review-coverage-audit': ['review/**', 'test/fixtures/coverage-audit-fixture.ts', 'test/skill-e2e-coverage-audit.test.ts'],
   'plan-eng-coverage-audit': ['plan-eng-review/**', 'test/fixtures/coverage-audit-fixture.ts', 'test/skill-e2e-coverage-audit.test.ts'],
   'ship-triage': ['ship/**', 'bin/gstack-repo-mode', 'test/skill-e2e-triage.test.ts'],
+  'ship-docsync': ['ship/**', 'document-release/**', 'scripts/gen-skill-docs.ts', 'scripts/resolvers/sections.ts', 'test/skill-e2e-ship-docsync.test.ts'],
 
   // Plan completion audit + verification
   'ship-plan-completion': ['ship/**', 'scripts/gen-skill-docs.ts'],
@@ -642,6 +643,7 @@ export const E2E_TIERS: Record<string, 'gate' | 'periodic'> = {
   'ship-local-workflow': 'gate',
   'ship-coverage-audit': 'gate',
   'ship-triage': 'gate',
+  'ship-docsync': 'gate',
   'ship-plan-completion': 'gate',
   'ship-plan-verification': 'gate',