fix(lint,command,scheduler): lpk alias, ReturnCount/IllegalCatch triage, scheduler facade

- command: replace /lp alias with /lpk (LuckPerms conflict, p.144);
  parkour alias kept; docs/changelog/javadoc updated
- lint p.169: restructure last 69 void early-returns into if-blocks and
  helpers; ReturnCount is now an error gate (0 violations)
- lint p.170: Throwable->RuntimeException on 3 boundaries; narrow 5
  catches to concrete types; document 14 intentional boundary catches
- scheduler p.21: add runTimerAsync to the facade (Bukkit + Folia
  backends); MetricsCacheStore and duels go through the facade, no
  BukkitRunnable/Bukkit.getScheduler outside scheduler/ (archunit
  freeze-store emptied); drop the unverified Folia badge from README
- tracker: mark p.26-29/32-33 done (fixed in fea15e6, verified)

README.md

@@ -6,7 +6,6 @@ Advanced infinitely generating parkour plugin with ghost system, leaderboards an
 
 ![Java](https://img.shields.io/badge/Java-21+-orange?style=flat-square&logo=openjdk&logoColor=white)
 ![Paper](https://img.shields.io/badge/Paper-1.19.2+-blue?style=flat-square)
-![Folia](https://img.shields.io/badge/Folia-supported-purple?style=flat-square)
 ![License](https://img.shields.io/badge/license-GPLv3-blue?style=flat-square&logo=gnu&logoColor=white)
 ![version](https://img.shields.io/badge/version-1.4.0-green?style=flat-square)
 
@@ -53,14 +52,14 @@ LoParkour is an advanced parkour plugin with infinite world generation. The cour
 
 | Command | Description |
 |---------|-------------|
-| `/lp join` | Join parkour |
-| `/lp leave` | Leave parkour |
-| `/lp spectate <player>` | Spectate another player |
-| `/lp schematic save <name>` | Save a schematic |
-| `/lp schematic reload` | Reload schematics |
-| `/lp schematic convert` | Convert old vilib format |
-| `/lp forcejoin <player>` | Force player to join (admin) |
-| `/lp reset` | Reset leaderboards (admin) |
+| `/lpk join` | Join parkour |
+| `/lpk leave` | Leave parkour |
+| `/lpk spectate <player>` | Spectate another player |
+| `/lpk schematic save <name>` | Save a schematic |
+| `/lpk schematic reload` | Reload schematics |
+| `/lpk schematic convert` | Convert old vilib format |
+| `/lpk forcejoin <player>` | Force player to join (admin) |
+| `/lpk reset` | Reset leaderboards (admin) |
 
 ### Dependencies
 
@@ -103,13 +102,13 @@ LoParkour - продвинутый паркур-плагин с бесконеч
 
 | Команда | Описание |
 |---------|----------|
-| `/lp join` | Начать паркур |
-| `/lp leave` | Выйти из паркура |
-| `/lp spectate <игрок>` | Наблюдать за игроком |
-| `/lp schematic save <имя>` | Сохранить схематику |
-| `/lp schematic reload` | Перезагрузить схематики |
-| `/lp forcejoin <игрок>` | Заставить игрока начать (админ) |
-| `/lp reset` | Сбросить лидерборды (админ) |
+| `/lpk join` | Начать паркур |
+| `/lpk leave` | Выйти из паркура |
+| `/lpk spectate <игрок>` | Наблюдать за игроком |
+| `/lpk schematic save <имя>` | Сохранить схематику |
+| `/lpk schematic reload` | Перезагрузить схематики |
+| `/lpk forcejoin <игрок>` | Заставить игрока начать (админ) |
+| `/lpk reset` | Сбросить лидерборды (админ) |
 
 ### Зависимости