feat: add dynamic fire dispatch and rollback

src/main/java/net/therosegarden/firefighter/FirefighterDutyManager.java

@@ -0,0 +1,69 @@
+package net.therosegarden.firefighter;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.bukkit.entity.Player;
+
+final class FirefighterDutyManager {
+    private final RoseFirefighterPlugin plugin;
+    private final JobsFacade jobs;
+    private final File file;
+    private final Set<UUID> offDuty = new HashSet<>();
+
+    FirefighterDutyManager(RoseFirefighterPlugin plugin, JobsFacade jobs) {
+        this.plugin = plugin;
+        this.jobs = jobs;
+        this.file = new File(plugin.getDataFolder(), "duty-status.yml");
+        load();
+    }
+
+    boolean isOnDuty(Player player) {
+        return player != null && jobs.isFirefighter(player) && !offDuty.contains(player.getUniqueId());
+    }
+
+    boolean setOnDuty(Player player, boolean onDuty) {
+        if (player == null || !jobs.isFirefighter(player)) {
+            return false;
+        }
+        if (onDuty) {
+            offDuty.remove(player.getUniqueId());
+        } else {
+            offDuty.add(player.getUniqueId());
+        }
+        save();
+        return true;
+    }
+
+    private void load() {
+        offDuty.clear();
+        if (!file.isFile()) {
+            return;
+        }
+        YamlConfiguration yaml = YamlConfiguration.loadConfiguration(file);
+        for (String value : yaml.getStringList("off-duty")) {
+            try {
+                offDuty.add(UUID.fromString(value));
+            } catch (IllegalArgumentException ignored) {
+                plugin.getLogger().warning("Ignoring invalid off-duty UUID: " + value);
+            }
+        }
+    }
+
+    void save() {
+        YamlConfiguration yaml = new YamlConfiguration();
+        yaml.set("off-duty", offDuty.stream().map(UUID::toString).sorted().toList());
+        try {
+            if (!plugin.getDataFolder().exists() && !plugin.getDataFolder().mkdirs()) {
+                plugin.getLogger().warning("Could not create plugin data folder for duty status.");
+                return;
+            }
+            yaml.save(file);
+        } catch (IOException ex) {
+            plugin.getLogger().severe("Could not save Firefighter duty status: " + ex.getMessage());
+        }
+    }
+}