feat(release): recursion guard for the health gate; run-task drift warning; M20 packages/* decision recorded (#39)

- release.sh health gate runs with MOSAIC_ENSURE_SKIP=1: the gated task run
  cannot re-enter release self-determination
- run-task.sh warns on release drift instead of silently using a stale image
- ROADMAP: M20 decision recorded (packages/* monorepo at usurpation,
  continuity-first); restructure sequenced as M20 phase 1

Closes #39

skills/ms-user/SKILL.md

@@ -4,5 +4,35 @@ description: Always use to update recorded information about the user
 disable-model-invocation: false
 ---
 
-# User
-Info about the tooling and usage should be listed here.
+# ms-user
+
+The user context layer holds user-owned information dispatched to every
+agent launch: everything under `<dataRoot>/user/`, with `USER.md` as the
+profile.
+
+## Rules
+
+1. The user owns the content. It is injected into your system prompt when
+   present; verify it on disk before editing.
+2. Always check for the `<dataRoot>/user/USER.md` file before attempting
+   to update info.
+3. If the USER.md file is missing, guide the user through onboarding
+   (`scripts/onboard.sh`) or, with their consent, create a minimal
+   template (name only) and let them fill in the rest.
+4. Initial configuration uses `scripts/onboard.sh`
+   (guided, name required) or the user's own edits.
+   Agents propose; the user decides and authorizes; once authorized,
+   the agent performs the edit.
+5. NEVER place secrets in the user layer. Everything under
+   `<dataRoot>/user/` is dispatched to every agent and worker, so keep
+   near-secrets out too: home address, finances, anything you would not
+   hand a stranger with shell access.
+6. Propose every change to the user layer, new content or new section
+   alike, and apply it only after an explicit yes.
+7. Propose updates proactively as information about the user is learned.
+8. The USER.md file is not limited to the provided template fields.
+   Add sections as needed.
+9. Never block work on proposed updates to the user information files.
+   Note the proposed additions in a scratch file outside
+   `<dataRoot>/user/` (unconfirmed content must not be dispatched),
+   then confirm with the user at a better time.