feat: OpenBao unseal custody models — automation-first with blocked alternatives

Document three init/unseal custody paths; default sops-held-automation for
fast rebuild cycles. Security bootstrap console lists models, blocks planned
attended-ceremony and auto-unseal-transit with hints, and gates init ceremony
on implemented selection. NET-WP-0020 tracks downstream SSH automation.

docs/openbao-unseal-custody-models.md

@@ -0,0 +1,105 @@
+# OpenBao Unseal Custody Models
+
+Date: 2026-06-17  
+Status: framework — automation path active; production paths planned
+
+NetKingdom bootstrap must support **three** OpenBao init/unseal custody models.
+Development starts with **maximum automation** for fast test cycles, then adds
+human custody gates as production trust increases.
+
+This is separate from **king custody mode** (`temporary-single-king`,
+`two-of-three-planned`, `two-of-three-ready`) which governs who holds platform
+recovery authority. Unseal custody models govern **how init/unseal executes**
+during bootstrap and rebuild.
+
+---
+
+## Models
+
+| Model ID | Label | Custody strength | Automation | Status |
+| --- | --- | --- | --- | --- |
+| `sops-held-automation` | SOPS-held unseal | Lab / fast iteration | High | **Implemented** (console + creds agent path) |
+| `attended-ceremony` | Attended ceremony | Production | Low | Planned |
+| `auto-unseal-transit` | Auto-unseal (transit/KMS) | Production HA | High | Planned |
+
+### `sops-held-automation` (default for greenfield dev)
+
+- Init/unseal material lives in **SOPS/age** custody bundle (not Git plaintext).
+- Applied by `sso-mfa/bootstrap/creds-bootstrap-agent.sh` and related `creds-apply`
+  tooling after cluster + OpenBao pod exist.
+- Enables **unattended rebuild test cycles** on a 3-node slate.
+- **Not** production trust posture — use to prove S1→S3→SSH engine automation,
+  then graduate to stronger models.
+
+### `attended-ceremony` (production target)
+
+- Human-attended `bao operator init`, out-of-band unseal share escrow, root token
+  retirement — per `railiance-platform/docs/openbao.md`.
+- Matches first successful NetKingdom bootstrap (NET-WP-0015–0017).
+- Console keeps **refuse-live-init** boundary; ceremony runbooks only.
+
+### `auto-unseal-transit` (production HA target)
+
+- OpenBao seal configuration uses **transit** or cloud KMS auto-unseal.
+- Pod restart without manual unseal threshold ceremony.
+- Requires `railiance-platform` Helm seal stanza + KMS provisioning.
+
+---
+
+## Development strategy
+
+```text
+1. Implement automation path (sops-held-automation)
+      → SSH engine, warden sign, host CA trust, 3-node rebuild loops
+2. Add attended-ceremony gates (block automation defaults in production profile)
+3. Add auto-unseal-transit for HA ThreePhoenix rebuilds
+```
+
+Each model is selectable in the **security bootstrap console**. Unimplemented
+models are **blocked** with a hint pointing to the active automation path.
+
+---
+
+## Console integration
+
+```bash
+# List models and implementation status
+python3 tools/security-bootstrap-console/security_bootstrap_console.py \
+  openbao-unseal-custody-models
+
+# Select active model (only implemented models succeed)
+python3 tools/security-bootstrap-console/security_bootstrap_console.py \
+  select-openbao-unseal-custody-model \
+  --model sops-held-automation \
+  --metadata .local/security-bootstrap.json
+
+# Status shows gate: "OpenBao unseal custody model"
+make security-bootstrap-console   # or: ... status --metadata .local/...
+```
+
+Metadata field: `openbao_unseal_custody_model`
+
+---
+
+## Automation chain (after model selected)
+
+| Step | Owner | Target |
+| --- | --- | --- |
+| S1 OS baseline | railiance-infra | 3 nodes |
+| S2 k3s HA | railiance-cluster | ThreePhoenix |
+| S3 OpenBao deploy | railiance-platform | `make openbao-deploy` |
+| Init/unseal apply | net-kingdom | `creds-bootstrap-agent.sh` (sops-held) |
+| Platform config | railiance-platform | `openbao-configure-initial` |
+| SSH engine | railiance-platform | `openbao-configure-ssh` (planned) |
+| Host CA trust | railiance-infra | `bootstrap-ssh-ca` (planned) |
+| Sign smoke | ops-warden | `warden sign` (WP-0008 T2) |
+
+---
+
+## Related docs
+
+- `docs/smooth-bootstrap-guide.md` — Step 5 (OpenBao init/unseal)
+- `docs/platform-root-custody.md` — king / quorum custody
+- `railiance-platform/docs/openbao.md` — deploy and ceremony
+- `ops-warden/wiki/OpenBaoSshEngineChecklist.md` — SSH engine verify
+- `ops-warden/history/2026-06-17-openbao-production-verify.md` — current blockers