test(e2e): periodic-tier repairs from the failure triage

Each fix traces to a receipt: brain-privacy-gate staged config never
reached the hermetic child (ambient GSTACK_HOME is scrubbed) and the
operator's remote-mode gbrain suppressed the gate — both now injected
per-test; ship-idempotency threw away its evidence on the timeout path
and ran a 600s budget its own subject can exceed (now 900s, evidence
captured); auto-decide-preserved gets the same headroom its sibling
plan-ceo tests got; context-skills' hides-checks scanned bash output
where an ls legitimately names old checkpoints (final-text scope now);
design names the missing section instead of a bare count and learns the
easing/duration/micro-interaction synonyms; qa-workflow's collector
afterAll gets an explicit 60s hook timeout.

test/skill-e2e-context-skills.test.ts

@@ -447,8 +447,13 @@ Do NOT use AskUserQuestion.`,
     // Match by filename timestamp (stable, unambiguous) plus a looser
     // prose check.
     const showsMain = /20260101-120000|main-work/.test(out);
-    const hidesAlpha = !/20260202-120000/.test(out);
-    const hidesBeta = !/20260303-120000/.test(out);
+    // Hide checks scope to the FINAL text output only: fullOutputSurface
+    // includes bash tool_results, and a legitimate `ls` of the checkpoint
+    // dir lists every branch's filename. The filtering under test happens
+    // in the user-facing list, not in the agent's intermediate reads.
+    const finalText = result.output ?? '';
+    const hidesAlpha = !/20260202-120000|LISTCURR_ALPHA_TOKEN/.test(finalText);
+    const hidesBeta = !/20260303-120000|LISTCURR_BETA_TOKEN/.test(finalText);
     const routed = skillCalls(result).includes('context-save');
     const exitOk = ['success', 'error_max_turns'].includes(result.exitReason);