feat(generator): improve jump generation and block placement logic

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.

.gitignore

@@ -52,7 +52,7 @@ build/
 gradle-app.setting
 !**/src/main/**/build/
 !**/src/test/**/build/
-
+run/
 # OS files
 .DS_Store
 Thumbs.db