ryu-predict 0.1.3

Predict: the system-wide predictive-typing brain for Ryu — an extracted Core capability crate owning the completion engine (config, per-app allowlist, secure-field denylist, prompt assembly, reply cleanup) and the `/api/predict/*` HTTP surface. In-process default; Core consumes it as a NON-optional path dependency. Every cross-cutting call it needs (preferences, the agent's bound model, the default model id, the Gateway side-model call, and the plugin-owned enabled flag) is inverted through the `PredictHost` trait so this crate has ZERO dependency on apps/core. The process-global on/off flag (`predict::set_enabled` / boot seeding) stays in the kernel — it is the built-in Predict plugin's switch.