refactor: decompose god-classes, add lint gates, restructure packages

- Decompose all 11 god-classes (>200 lines) into facade + collaborators
  (command/, schematic/, config/, generator/, mode/, papi/, adaptive/,
  storage/, player/, leaderboard/) — every file is now <=200 lines
- Add PMD 7 (report-only) + stricter checkstyle rules (NPath, IllegalCatch,
  NestedDepth, Whitespace, MissingOverride); fix real bugs found
  (printStackTrace, resource leaks in ConfigLoader/SQLStatsStorage)
- docs/ARCHITECTURE.md: target structure + 'one folder = one purpose' rule
- Pilot restructure: command/core|util/, mode/impl/solo|multi|barrier/,
  hook/papi/resolver/; cross-package classes made public
- TODO.md: track warning cleanup (132-138) + restructure progress

src/main/java/dev/loki/loparkour/hook/papi/PlaceholderDispatcher.java

@@ -0,0 +1,23 @@
+package dev.loki.loparkour.hook.papi;
+
+import dev.loki.loparkour.hook.papi.resolver.GlobalPlaceholderResolver;
+import dev.loki.loparkour.hook.papi.resolver.PlayerPlaceholderResolver;
+import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
+
+class PlaceholderDispatcher {
+
+    private final GlobalPlaceholderResolver globalResolver = new GlobalPlaceholderResolver();
+    private final PlayerPlaceholderResolver playerResolver = new PlayerPlaceholderResolver();
+
+    String dispatch(Player player, @NotNull String params) {
+        String resolved = globalResolver.resolve(params);
+        if (resolved != null) {
+            return resolved;
+        }
+        if (player == null) {
+            return "player doesn't exist";
+        }
+        return playerResolver.resolve(player, params);
+    }
+}