8988b16bee
- Fix `ref` keyword used as variable name in code examples - Fix "retries next tick" → systems continue on normal schedule - Fix `State::set()` → `NextState::set()` in upgrade skill - Fix `SceneRoot` → `WorldAssetRoot` for 0.19 consistency - Fix Replace lifecycle event description (overwritten, not removed) - Fix grep patterns (quoting, trailing spaces) - Remove third-party physics/networking content (not Bevy built-ins)