Prevent Experiment lifecycle CI deadline failures

[xor-machine]

Summary

• split the Experiment lifecycle Fast aggregate into independently deadline-bound onboarding and install suites
• preserve the original 133-assertion compatibility route and the measured three-lane topology
• add fail-closed route, tail, and missing-core contracts

Why

A hosted Fast run reached the unchanged 120-second per-suite deadline while executing the combined Experiment lifecycle aggregate. The approved CI plan requires splitting aggregates that reach this bound. No timeout, retry, skip, worker, or aggregate-deadline limit is raised or bypassed.

Evidence

• slice PR Split Experiment lifecycle CI deadline load #44 integrated after every hosted check passed
• RED commits demonstrate manifest/routing failure and adversarial wrong-route, orphan-tail, missing-core, and topology failures
• GREEN partitions all 133 assertions exactly as 86 + 47 while retaining the no-argument compatibility contract
• concurrent route timings: onboarding 52.48s; install lifecycle 54.37s
• final ./scripts/dev/check default quick: pass=33 fail=0 skip=0 infra=0
• final ./tools/validate.sh --strict: PASS
• hosted slice checks: Fast, Static, Docker security, CodeQL, and Required gates all passed

Scope

Six lifecycle test/manifest files only. No feature, rail, workflow, containment, or approved deadline changes.