Refactor the parkour generator to improve jump accuracy, block placement, and lifecycle management.
- Improve jump calculation by normalizing heading vectors and adjusting height/distance constraints.
- Implement height overrides for tall materials (fences, trapdoors, glass panes) during block placement.
- Add difficulty-based special block generation (packed/blue ice).
- Fix block identity issues by using coordinate-based comparison instead of reference equality for scoring and cleanup.
- Optimize generation lead to reduce unnecessary block generation.
- Update leaderboard logic to only replace scores if the new score is strictly better (higher score or faster time).
- Add error handling for generator ticks to prevent session crashes.
build: update build configuration and dependencies
- Add `run-paper` plugin for easier local server testing.
- Update Gradle wrapper to version 8.14.3.
- Change WorldEdit dependencies to `compileOnly`.
- Configure `runServer` task with Minecraft 1.21.4 and PlaceholderAPI.
fix(ui): improve scoreboard placeholder handling
- Add check for PlaceholderAPI plugin enablement before attempting to use it.
