AUD-56: deploy prep - token script, container user fix, runbook

- Add scripts/provision-hub-tokens.sh. It adds the five HUB_TOKEN_* keys to
  ~/.config/environment.d/10-secrets.conf. It is idempotent, keeps mode 600,
  leaves a mode-600 backup, and never prints a value. It uses openssl when
  present and /dev/urandom otherwise (this host has no openssl).
- docker-compose.yml: run the container as the host user. The image's
  distroless nonroot user cannot read the 0600 secrets file. With nonroot the
  Hub read no tokens and every /ask returned 401.
- Document the deploy steps, the finding, and the dry-run evidence in
  docs/outline/04-agent-runbook.md, docs/outline/02-config-and-env.md, README.md.

Dry run on port 18788 with a scratch secrets file: /health ok with
omniroute ok, control action refused, bad token 401. The host secrets file and
the running hub container were not touched.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

README.md

@@ -35,6 +35,9 @@ curl -s -X POST http://192.168.20.13:8788/ask \
 
 The Hub reads `HUB_TOKEN_*`, `OMNIROUTE_API_KEY`, and the project tokens from
 `~/.config/environment.d/10-secrets.conf` (mounted read-only, never committed).
+Add the five Hub client tokens with the idempotent script
+`scripts/provision-hub-tokens.sh`; it keeps mode 600 and never prints a value.
+A new token needs Sam's OK (`AGENTS.md` "ask first: credentials").
 
 ### Test without a network