docs(apsuflow): explain migration acknowledgments

skills/apsuflow/SKILL.md

@@ -44,17 +44,14 @@ in the same change when applicable requirements or CLI behavior change.
   not add quorum votes.
 - One signed `apsuflow` executable runs on every supported Linux profile;
   profiles contain only host configuration and service scripts. The daemon never
-  detects a distribution, libc, or init system. Before opening its listener it
-  must prove its unprivileged effective UID and create/remove a child beneath a
-  writable delegated cgroup v2 parent exposing `cpu`, `memory`, and `pids` while
-  the daemon itself remains in a leaf cgroup. On systemd profiles this requires
-  `Delegate=yes` plus `ProtectControlGroups=private`; Apsuflow then moves itself
-  into `/daemon` before proving or creating workload children.
-  `doctor` reports the same kernel-observed parent-process and cgroup facts.
-  Failure is closed: there is no root or service-manager-specific fallback.
-  Both release-supported profiles have complete acceptance proof, including the
-  Void-musl/runit PID-1 path in a local KVM/QEMU VM with a real OCI workload,
-  restart, limits, and encrypted backup/restore.
+  detects a distribution, libc, or init system. The control-plane server runs as
+  the locked `apsuflow` user with zero effective Linux capabilities and access
+  only to its state directory and listener. A separately supervised,
+  capability-bounded root agent owns OCI, namespace, cgroup, CNI, firewall,
+  host-path, and host-network effects. Missing agent prerequisites leave
+  workloads stopped; the server never becomes an execution fallback. Both
+  release-supported profiles prove a real agent-owned OCI workload, independent
+  server and agent restart, and encrypted control-plane backup/restore.
 - `.apsu` contains desired workloads and infrastructure, never secret values or
   mutable runtime state.
 - Services are continuously reconciled. Jobs are finite run-to-completion work.
@@ -87,7 +84,24 @@ must converge after re-apply.
 
 ## Install and update
 
-Use only the exact stable tag and artifact named by `docs/getting-started.md`.
+For an existing legacy root daemon, use `apsuflow host migrate` rather than
+manually replacing the service. Prepare canonical declarations and separate,
+encrypted backup archive/key restore evidence; run the command without
+`--commit` first and review its state classification. Unknown state, an
+unidentified supervisor, an existing split profile, invalid backup evidence, or
+invalid persisted image references must stop before effects. If no unused
+bootstrap token remains, provide a retained administrator token file and create
+the node-bound `solo-agent` join token through the public CLI before shutdown;
+supply them with `--admin-token` and `--agent-token`. Pass
+`--allow-secret-env` and `--acknowledge-recovery-risk` when the reviewed
+migration declaration requires those same explicit apply acknowledgments.
+Commit as root only after review; it quiesces persisted services and reapplies
+the exact declarations through public controls. Retain its rollback
+directory until the split services, exact declaration reapply, and
+application-level data checks pass. Never recursively chown workload data or
+repair migration through SQLite, OCI, CNI, firewall, or namespace mutation.
+
+Use only the exact release tag and artifact named by `docs/getting-started.md`.
 Official bootstrap and Cloud-Init entry points require that exact version,
 verify `SHA256SUMS` with the repository-pinned SSH release identity, verify the
 selected archive hash, replace atomically, and retain `apsuflow.previous`; never
@@ -107,10 +121,9 @@ the control plane.
 
 For host-network workloads, confirm the old container released its host ports and
 the successor is the sole running generation; repeated replacement failures are
-a rollback signal, not a reason to mutate runtime state directly. The first
-stable release has no predecessor compatibility case; every later stable release
-must carry proved upgrade and rollback evidence against its adjacent stable
-predecessor. Apsuflow is not published to a Cargo registry.
+a rollback signal, not a reason to mutate runtime state directly. Every
+successor release must carry proved upgrade and rollback evidence against its
+preceding supported artifact. Apsuflow is not published to a Cargo registry.
 
 ## Local operation
 
@@ -128,15 +141,22 @@ Use `fmt` without `--check` only when reformatting is intended. Use `apply
 removed. Validation reports portability limits before mutation. Capabilities
 whose failure can require manual recovery—host networking, devices, and writable
 host paths—also require `apply --acknowledge-recovery-risk`; read the reported
-source location and consequence before accepting it. Verify the actual route or
-job result; a successful apply alone proves only admission.
+source location and consequence before accepting it. A volume source is itself
+an exact hard placement requirement; do not duplicate it in `.apsu` constraints.
+On each execution host, list the roots the agent may provide, one absolute path
+per line, in root-owned mode-0600 `/etc/apsuflow-agent/host-paths`, then restart
+the agent. A listed root grants authority; it need not pre-exist. The agent
+creates a missing volume directory only below a listed root and rejects paths
+outside those roots or through symlinks. Container entrypoints initialize
+application content, not host placement. Verify the actual route or job result;
+a successful apply alone proves only admission.
 
-The server daemon runs unprivileged in its delegated cgroup; the agent remains
-rootful only for its authorized runtime and host-network effects. Do not run
-client commands with `sudo`: protect daemon state and use an operator context or
-token. Join credentials are node-bound, role-bound, single-use, and expire after
-15 minutes; never reuse, commit, or broaden them. `server --no-auth` is
-acceptable only for disposable loopback use.
+The server daemon runs unprivileged without runtime capabilities; the separately
+supervised agent remains rootful only for its authorized runtime and host effects.
+Do not run client commands with `sudo`: protect server state and use an operator
+context or token. Join credentials are node-bound, role-bound, single-use, and
+expire after 15 minutes; never reuse, commit, or broaden them. `server --no-auth`
+is acceptable only for disposable loopback use.
 
 ## Multiple environments
 
@@ -200,7 +220,9 @@ job backup {
 - Reference secret names and set values with `apsuflow secret set`; never embed
   secret values in `.apsu`.
 - Routes are L4 TCP/UDP forwarding, not HTTP hostname routing or application TLS.
-- Writable host paths are node-local and need placement plus separate data backup.
+- Writable host paths are node-local; their volume sources imply placement, the
+  agent's root-owned `host-paths` file declares availability, and data needs a
+  separate backup.
 - Use a service plus an external broker for consumers; use a job for bounded
   migration, backup, maintenance, or scheduled work.
 - Scheduled declarations create job runs; inspect them with `apsuflow job runs