Added the first single-binary migration step: Pod runtime startup is now available as a shared `pod::entrypoint` library path, the existing `insomnia-pod` binary is a temporary thin wrapper, and the user-facing `insomnia` binary now supports `insomnia pod ...` with the same Pod runtime parser/help. Existing internal spawn defaults and Nix packaging are intentionally unchanged for this step. External review approved and validation passed.
