Add scoped provisioning for prepared coding-agent instances

[witbrock]

Von previously needed operator-specific manual setup for every coding worker. This adds an actor-scoped lifecycle for approved host/account/identity slots, coherent release reconciliation, canonical identity/membership creation, retained pause/resume/settings, generic sender attribution and inherited host-wide memory admission.

Current-main integration preserves task timing, token accounting, retry/supervision and federation routing. Live acceptance found and fixed the missing-concept adapter contract and systemd EnvironmentFile path escaping.

Merge is ready. One temporary, separately attributed Astra/high instance completed its canonical canary task, consumed a verified attachment, produced the correct artefact, and sent its result with intended-recipient read-back. Another organisation's provisioning request and an unrelated private attachment were denied. Repeated reconciliation and a killed provisioner recovered without duplicate identity/unit; an actual busy-host poll refused admission. Timing/message replay preserved one completion. The temporary unit was retired; no permanent consumer or public deployment was activated.

Validation:

• 124 focused lifecycle, worker/inbox, capacity, release and timing checks pass; two optional Mac bridge checks skipped.
• Actual systemd resource/environment read-back, inherited-lock contention, interrupted provisioning, canonical task/attachment/result and recipient evidence.
• Ruff and diff checks; current GitHub syntax and secret checks.

Same prepared Unix account only: separate-account authentication/isolation is unverified. Partial root token usage is recorded; monetary cost remains unknown. Operator enrolment and credential preparation remain required.

Native source task: #V#task_agent_002b293c463ed8e1e52df23cb68f9612. Live acceptance task: #V#task_agent_e432b713af2eaa9a9393d113d8b5eab0; full receipt attached to the source task. Parent VS Code owner handles canonical bridge reconciliation and the separately authorised final deployment.

[witbrock]

Quick integration review against main a607464: merge decision remains not ready. Dry merge conflicts in codex_von_worker.py include display_name versus agent_name, explicit retry instructions, and continuation-admission reporting. Retain current retry/supervision/federation behaviour while adding instance lifecycle/capacity support; do not resolve by wholesale replacement with the old worker. Verify the existing worker and Mac task adapter with the integrated release. The host-capacity mechanism intentionally holds one exclusive slot: its configured effect on existing workers/inbox progress must be explicit. Merge this core integration before dependent PR684; source merge does not establish installed controller compatibility.