0.1.2

• Client.from_env/AsyncClient.from_env now auto-select an installed
  local backend (laya_mlx or laya) with zero configuration: no
  environment variable is required, and DECIDE_LOCAL_MODEL becomes an
  optional override of the backend's own default model instead of a
  requirement to opt in. A local backend, when importable, is tried before
  the hosted backends as a fallback chain; decide backends reports its
  CONFIGURED column as default in this state.
• The ConfigError raised when nothing is configured now ends with
  concrete next steps: which extra to install for a local backend, or which
  environment variable to set for a hosted one.