[cocolord]

Outcome

Advance the accepted M1 namespace regrouping with one reversible, behavior-preserving server-entry slice.

• Move chat_session_open.py and chat_ssh_source_api.py under loopx.chat.
• Update their only production consumer, focused imports, and mock patch targets.
• Remove both old top-level paths without compatibility shims: repository inventory found no established docs, examples, or package import contract.
• Lower the top-level module budget from 136 to 134, matching the exact net removal.

Stack and boundary

• Stacked on refactor(chat): move internal APIs under chat namespace #7883 (codex/small-kernel-m1-chat-slice2-20261102) at 53435870b; refactor(chat): colocate configuration APIs #7891 merged into this base while the slice was being validated.
• Exact head: 55cda8585.
• Structural ownership change only: no runtime behavior, defaults, authority, activation, or performance claim changes.
• Runtime change retains normal maintainer merge authority; this PR must not be self-merged.

Validation

• 69 passed: internal layout/budget, native steward session opening, and SSH source/lifecycle behavior.
• examples/loopx-chat-server-smoke.py: real source Chat server path passed.
• Source Chat bundle verification passed.
• Isolated wheel import check proved both new modules ship, both old paths are absent, and loopx.chat_server imports outside the checkout.
• Installed-wheel Chat HTTP delivery passed for entry, current/previous assets, and PWA files.
• Diff-scoped semantic advisory found no supported new vocabulary carriers.
• Rebase tree equality proved the validated product tree was unchanged after refactor(chat): colocate configuration APIs #7891 entered the stack base.
• Exact-head standard premerge against 53435870b passed all direct checks and 2/2 selected catalog canaries.

Generated frontend assets, dependency trees, build output, and uv.lock were removed after validation.