fix: lazy runtime imports in facades to break bundle cycles

All service facades now use @/effect/run (lazy runtime import) instead
of directly importing @/effect/runtime. This breaks the circular
dependency chain that caused "undefined is not an object" crashes in
bun's bundled binary.

- Add src/effect/run.ts with run() and runInstance() lazy wrappers
- Strip all facades to runtime-only functions (no schema re-exports)
- Consumers that need schemas import from service modules directly
- Update specs/effect-migration.md with facade rules and full list