docs/spark-control-integration.md: the SSH command contract (status via
docker inspect; restart via docker restart; update via git fetch + reset
--hard origin/master + docker compose up -d --build) plus the one-time
conversion of the Spark's ~/matrix-bridge to a Gitea clone. No bot code
change. Update source = git-pull-from-Gitea; rides Spark Control's existing
SSH into spark-32d0 (no new key). Corrected the infra note: Spark is on the
LAN with the Start9/Gitea host, so Spark->Gitea resolves directly.
Keysat