No minimum password length, and say how to reset it

The script refused anything under ten characters. That is a policy the owner
should hold, not one the tooling invents; the only rule left is that the password
cannot be empty, since an empty one would let anyone in. Resetting is the same
script with --force, which overwrites the hash and generates a fresh session
secret, signing out anyone who was signed in - now written down in the operating
notes and the deployment readme, including the form that prompts on your own
machine instead of the server.

scripts/provision-site-env.sh

@@ -95,10 +95,6 @@ if [[ "$PASSWORD" != "$REPEAT" ]]; then
   echo "the passwords do not match" >&2
   exit 1
 fi
-if [[ ${#PASSWORD} -lt 10 ]]; then
-  echo "use at least 10 characters" >&2
-  exit 1
-fi
 
 HASH="$(printf '%s' "$PASSWORD" | docker run --rm -i --entrypoint node "$IMAGE" \
   --input-type=module \