chore(openspec): archive lifecycle-engines-core-internal-l3

[Drswith]

Summary

Archive completed OpenSpec change lifecycle-engines-core-internal-l3 after its implementation PR (#724) merged, syncing the accepted runtime-boundaries and compatibility-contract deltas into openspec/specs/.

Main specs now require agent-observation, update-planner, agent-execution, and uninstall-postcondition to live in Core-internal modules under src/core/lifecycle/, keep the remaining src/lifecycle barrel outside Core until a later knife, and freeze v1 JSON/aliases/exit codes/state v2 plus the published quantex-core export list across that internalization.

Also adds a one-line keep comment under src/core/lifecycle/ so classify sets run_test_matrix=true and test (macos-latest) actually runs (protect-main requires it; pure openspec PRs would otherwise skip macOS). This is archive-only: it does not delete src/lifecycle/ (L4).

Linked Artifacts

• Issue: refactor(core): move remaining lifecycle engines into Core-internal #724
• ADR: docs/adr/0013-core-internal-lifecycle-engines.md
• OpenSpec: lifecycle-engines-core-internal-l3

Validation

• bun run openspec:validate
• bun run memory:check
• bun run lint
• bun run format:check
• bun run typecheck

bun run test is not applicable for behavior: the only src/ edit is a one-line keep comment with no runtime effect. Full CI matrix (including macOS) is expected after this push.

Release Intent

• Release: not applicable - OpenSpec archive closure only

Release Summary

• Not applicable - OpenSpec archive closure does not produce a release entry. Internal changelog for the L3 engines move is already covered by the refactor(core): move remaining lifecycle engines into Core-internal #724 commit override.

Docs Updated

• openspec/...

Scope Check

• I did not add a new ad hoc root-level Markdown file.
• I updated the relevant issue, ADR, spec, runbook, or captured the missing doc work as follow-up.
• I did not silently expand project scope without recording it explicitly.

Closure Check

• Working tree was clean before archive closure started.
• Branch was pushed and this PR is the active delivery artifact.
• OpenSpec change is already archived or queued for agent-driven archive closure.
• Release is not applicable, delegated to release automation, or verified.

Notes

• Generated by bun run openspec:archive-closure -- lifecycle-engines-core-internal-l3 --apply-specs. refactor(core): move remaining lifecycle engines into Core-internal #724 did not apply living specs, so this archive used --apply-specs rather than --skip-specs.
• The L3 delta listed Remaining src/lifecycle barrel SHALL stay outside Core until a later knife as ADDED. Living specs already had L1's Remaining src/lifecycle engines SHALL stay outside Core until a later knife. Archive-time recast that requirement to MODIFIED so --apply-specs could replace the L1 remaining-engines text instead of leaving a contradictory ADDED header beside it. The generated openspec/changes/archive/2026-09-07-lifecycle-engines-core-internal-l3/ directory was removed rather than committed, matching chore(openspec): archive fix-upgrade-unresolved-latest-crash #707, chore(openspec): archive cli-core-upgrade-p6 #712, chore(openspec): archive cursor-version-probe-targeting #720, chore(openspec): archive lifecycle-model-core-internal-l1 #722, and every archive PR since 2026-08-16.
• Product-path keep comment hangs on still-existing src/core/lifecycle/uninstall-postcondition.ts (the L3 destination of that helper) so classify sets run_test_matrix=true. It does not touch src/lifecycle/ files that L4 may delete.
• This PR is archive only. It does not start L4 and does not delete src/lifecycle/.
• Did not touch shelved changes release-one-line-delivery, release-pr-skip-human-heuristics, or windows-ci-advisory-merge-gate.
• Did not start or conflict with the L2 OpenSpec archive of lifecycle-provider-core-internal-l2 beyond independently applying L3's own spec deltas.
• No YAML. No SDK. No CLI behavior change in this PR. No protect-main change.