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)

src/main/java/dev/loki/loparkour/config/locale/LocaleLoader.java

@@ -41,6 +41,7 @@ public final class LocaleLoader {
 
             return loadFromDisk(embedded);
         } catch (Exception ex) {
+            // Boundary: locale loading must never break enable; disk files may be corrupt.
             plugin.getLogger().severe("Error while loading locale files: " + ex.getMessage());
             return Collections.emptyMap();
         }