refactor(status): move status contract projection into bounded module

[huangruiteng]

Change

Q4 first real replacement slice: build_status_contract and build_contract_health_projection move into loopx/control_plane/status/contract_projection.py, including their status-contract constants.

loopx/status.py keeps the public compatibility functions as thin local wrappers and retains the public constants that existing smokes read from the facade.

Surfaces

• loopx/control_plane/status/contract_projection.py: new bounded status presentation module.
• loopx/status.py: facade wrappers delegate to the bounded module.

Validation

• Full pytest: 2306 passed, 2 skipped.
• Focused status/contract + import-boundary + maintainability ratchet: 26 passed.
• Ruff: All checks passed.
• loopx canary premerge --from-git-diff: passed, selected=17 failures=0, self_merge_allowed=true.

No failures or skips beyond the pre-existing suite skips. No manual holds.

Routing

Route: codex-side-bypass; not assigned to codex-quality-qualification.

[huangruiteng]

Review: APPROVED

head b9d429643。这是对 PR #2967 的完整 owner review。该 PR 是 M6 Q4 的第一片真实替换：build_status_contract 与 build_contract_health_projection 迁入 loopx/control_plane/status/contract_projection.py，loopx.status 保留薄兼容壳。

验证

• 全量 pytest：2306 passed, 2 skipped
• 聚焦 status/contract + import-boundary + maintainability ratchet：26 passed
• ruff：通过
• loopx canary premerge --from-git-diff：selected=17 failures=0，self_merge_allowed=true
• GitHub checks：dependency-review / pytest / build 全部通过

结论

无 blocker。状态 contract 投影现在位于 bounded status context，公共 facade 行为保持。按仓库 merge policy 路由合并。