Release 0.14.0

Added

• Middleware priority — Middleware base class now accepts priority: int (0-1000, default 0). Higher priority executes first; equal priority preserves registration order. BeforeMiddleware and AfterMiddleware adapters also accept priority.
• Priority range validation — ValueError raised for priority values outside 0-1000

Breaking Changes

• Middleware default priority changed from 0 to 100 per PROTOCOL_SPEC §11.2. Middleware without explicit priority will now execute before priority-0 middleware.