- Replaced relative `../src` imports with `@oh-my-pi/pi-ai` and `@oh-my-pi/pi-agent-core` subpaths.
- Added dependency-free `@oh-my-pi/pi-ai/effort` module and re-exported `Effort`/`THINKING_EFFORTS`. - Moved `Effort` and `THINKING_EFFORTS` from `model-thinking.ts` to `effort.ts`, then migrated runtime/tests imports.
fixes #773