docs: state current behaviour without change-log wording

docs/agent-lifecycle/persistence.md

@@ -215,7 +215,7 @@ Three indices:
 - `(node_id)` — added by a later migration so a build log row can be
   looked up by the job-queue node it belongs to (a `hive_jobq` node is
   immutable after insert, so hive-c0re records the link on the log row
-  instead); rows predating the column have `node_id IS NULL`.
+  instead); `node_id` is nullable.
 
 Writes are best-effort: `append_stdout` / `append_stderr` / `finish`
 log a warning on sqlite error and let the build continue. A failed
@@ -298,11 +298,9 @@ Under `/var/lib/hyperhive/agents/<name>/`:
     `hive-forge-notify` — upsert keyed todos here over the harness's
     in-agent socket, `HIVE_AGENT_SOCKET`; the harness merges them into
     `get_loose_ends` output and clears a row on `mark_todo_done`).
-    Consolidates todos and reminders into one file. A one-time boot
-    migration (`db_migrate::run`) folds any pre-existing files
-    (`hyperhive-todos.sqlite`, `hyperhive-reminders.sqlite`, the older
-    file-based `mcp-loose-ends/` scanner) into this path the first time
-    a harness boots. Also backs the `mcp__hyperhive__remind` queue.
+    At boot, `db_migrate::run` creates this file from
+    `hyperhive-todos.sqlite` and `hyperhive-reminders.sqlite` when those
+    are present. Also backs the `mcp__hyperhive__remind` queue.
 
     The harness itself is also a producer, not just the socket server:
     boot wiring's `spawn_todo_socket` starts `todo_server::run` (the
@@ -507,9 +505,8 @@ reinstall.
 
 The harness runs as a per-agent unix user inside the container
 (`services.hyperhive.agent.user.name`, defaults to the agent's logical label so each
-container has a uniquely named user). Operators with root-owned
-state dirs need a one-time data shuffle so they don't lose their claude
-session.
+container has a uniquely named user). The activation script below
+moves root-owned state to the agent user so the claude session survives.
 
 `system.activationScripts.hive-agent-user-migrate` (in
 `nix/agent-modules/user.nix`) runs on every activation,
@@ -543,8 +540,6 @@ container lifetime:
    there as the agent user. Why the mode matters:
    [`boundary.md`](../trust-boundary/boundary.md#the-per-agent-socket-dir).
 
-The activation script migrates any root-owned state dir still present.
-
 ## Matrix per-agent daemon + token-arrival trigger
 
 `hive-matrix-daemon` is a long-running matrix-sdk Client + sync