pi-toolchain: v0.4.0

Minor Changes

• 346fee2: Feature modes: rewriter features now support "disabled" | "rewrite" | "block" instead of booleans. In "block" mode the bash tool is not overridden — commands are blocked via tool_call hook instead. Config is auto-migrated on first load. preventBrew and preventDockerSecrets have been removed; use @aliou/pi-guardrails instead.