Rich per-player stats + pick-your-metric leaderboard

- lib/player-stats.ts: single computePlayerStats() reads every
  world/stats/<uuid>.json plus world/advancements/<uuid>.json and joins
  with usercache.json. Returns a flat PlayerStats record per player:
  playtime, longest life, mob/player kills, deaths, K/D, damage dealt
  and taken (HP-scaled), blocks mined, items used / crafted / picked up
  (+ unique), distance (summed across all _one_cm stats), chest opens,
  nether/end trips, villager trades, fish caught, animals bred, and
  advancements (non-recipe) / recipes unlocked.
- New GET /api/players/stats (authed, 60s memo). Existing
  /api/players/playtime now returns a thin projection of the same
  computed data (shared cache key keeps both endpoints cheap).
- New components/Leaderboard.tsx with a metric select grouped into
  Time / Combat / World / Exploration / Progression / Economy (22
  metrics). Sorts descending, top 10 with "show all" toggle, smart
  number formatting (1.2k / 3.4M / HP / km). Replaces the old
  PlaytimeLeaderboard in the Players tab.
- PlayerDrawer upgraded: uses the full stats payload, shows small
  tiles for Kills / Deaths / K/D / Advs / Mined / Crafted / Distance
  alongside Playtime + Last seen.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/player-stats.ts

@@ -0,0 +1,200 @@
+import { readFileSync, readdirSync, statSync, existsSync } from "fs";
+import { join } from "path";
+
+const STATS_DIR = "/home/minecraft/server/world/stats";
+const ADVANCEMENTS_DIR = "/home/minecraft/server/world/advancements";
+const USERCACHE = "/home/minecraft/server/usercache.json";
+
+const TICKS_PER_HOUR = 20 * 60 * 60;
+const TICKS_PER_SECOND = 20;
+
+export type PlayerStats = {
+  uuid: string;
+  name: string;
+  lastPlayedMs: number;
+
+  // Time
+  playtimeHours: number;
+  longestLifeHours: number;
+
+  // Combat
+  mobKills: number;
+  playerKills: number;
+  deaths: number;
+  kdr: number;
+  damageDealt: number; // HP (scaled /10 from raw)
+  damageTaken: number;
+
+  // World interaction
+  blocksMined: number;
+  itemsUsed: number; // approximates blocks placed + items consumed
+  itemsCrafted: number;
+  itemsPickedUp: number;
+  uniqueItemsPickedUp: number;
+
+  // Exploration
+  distanceKm: number; // all *_one_cm divided by 100_000
+  chestOpens: number;
+  netherPortalEnters: number;
+  endPortalEnters: number;
+
+  // Social / economy
+  villagerTrades: number;
+  fishCaught: number;
+  animalsBred: number;
+
+  // Progression
+  advancements: number; // excluding recipe advancements
+  recipesUnlocked: number;
+};
+
+type UserCacheEntry = { name: string; uuid: string };
+
+type StatsFile = {
+  stats?: {
+    "minecraft:custom"?: Record<string, number>;
+    "minecraft:mined"?: Record<string, number>;
+    "minecraft:used"?: Record<string, number>;
+    "minecraft:crafted"?: Record<string, number>;
+    "minecraft:picked_up"?: Record<string, number>;
+  };
+};
+
+type AdvancementFile = Record<string, { done?: boolean } | number>;
+
+function loadNameMap(): Map<string, string> {
+  try {
+    const arr = JSON.parse(readFileSync(USERCACHE, "utf8")) as UserCacheEntry[];
+    return new Map(arr.map((e) => [e.uuid, e.name]));
+  } catch {
+    return new Map();
+  }
+}
+
+function sumValues(obj: Record<string, number> | undefined): number {
+  if (!obj) return 0;
+  let total = 0;
+  for (const k in obj) total += Number(obj[k]) || 0;
+  return total;
+}
+
+function countKeys(obj: Record<string, number> | undefined): number {
+  if (!obj) return 0;
+  return Object.keys(obj).length;
+}
+
+function get(custom: Record<string, number> | undefined, key: string): number {
+  return Number(custom?.[key] || 0);
+}
+
+function readAdvancements(uuid: string): { advancements: number; recipes: number } {
+  const path = join(ADVANCEMENTS_DIR, `${uuid}.json`);
+  if (!existsSync(path)) return { advancements: 0, recipes: 0 };
+  try {
+    const data = JSON.parse(readFileSync(path, "utf8")) as AdvancementFile;
+    let advancements = 0;
+    let recipes = 0;
+    for (const id in data) {
+      const entry = data[id];
+      if (typeof entry !== "object" || entry === null) continue;
+      if (!entry.done) continue;
+      if (id.startsWith("minecraft:recipes/")) recipes++;
+      else advancements++;
+    }
+    return { advancements, recipes };
+  } catch {
+    return { advancements: 0, recipes: 0 };
+  }
+}
+
+export function computePlayerStats(): PlayerStats[] {
+  const names = loadNameMap();
+
+  let files: string[];
+  try {
+    files = readdirSync(STATS_DIR).filter((f) => f.endsWith(".json"));
+  } catch {
+    return [];
+  }
+
+  const out: PlayerStats[] = [];
+  for (const file of files) {
+    const uuid = file.replace(/\.json$/, "");
+    const path = join(STATS_DIR, file);
+    try {
+      const data = JSON.parse(readFileSync(path, "utf8")) as StatsFile;
+      const custom = data.stats?.["minecraft:custom"];
+      const mtime = statSync(path).mtimeMs;
+
+      const playtimeTicks = get(custom, "minecraft:play_time");
+      const longestLifeTicks = get(custom, "minecraft:time_since_death");
+
+      const mobKills = get(custom, "minecraft:mob_kills");
+      const playerKills = get(custom, "minecraft:player_kills");
+      const deaths = get(custom, "minecraft:deaths");
+      const kdr = deaths === 0 ? mobKills : mobKills / deaths;
+
+      const distanceCm =
+        get(custom, "minecraft:walk_one_cm") +
+        get(custom, "minecraft:sprint_one_cm") +
+        get(custom, "minecraft:crouch_one_cm") +
+        get(custom, "minecraft:swim_one_cm") +
+        get(custom, "minecraft:fly_one_cm") +
+        get(custom, "minecraft:boat_one_cm") +
+        get(custom, "minecraft:horse_one_cm") +
+        get(custom, "minecraft:minecart_one_cm") +
+        get(custom, "minecraft:pig_one_cm") +
+        get(custom, "minecraft:strider_one_cm") +
+        get(custom, "minecraft:climb_one_cm") +
+        get(custom, "minecraft:fall_one_cm") +
+        get(custom, "minecraft:aviate_one_cm");
+
+      const adv = readAdvancements(uuid);
+
+      out.push({
+        uuid,
+        name: names.get(uuid) || uuid.slice(0, 8),
+        lastPlayedMs: mtime,
+
+        playtimeHours: round2(playtimeTicks / TICKS_PER_HOUR),
+        longestLifeHours: round2(longestLifeTicks / TICKS_PER_HOUR),
+
+        mobKills,
+        playerKills,
+        deaths,
+        kdr: round2(kdr),
+        damageDealt: Math.round(get(custom, "minecraft:damage_dealt") / 10),
+        damageTaken: Math.round(get(custom, "minecraft:damage_taken") / 10),
+
+        blocksMined: sumValues(data.stats?.["minecraft:mined"]),
+        itemsUsed: sumValues(data.stats?.["minecraft:used"]),
+        itemsCrafted: sumValues(data.stats?.["minecraft:crafted"]),
+        itemsPickedUp: sumValues(data.stats?.["minecraft:picked_up"]),
+        uniqueItemsPickedUp: countKeys(data.stats?.["minecraft:picked_up"]),
+
+        distanceKm: round2(distanceCm / 100_000),
+        chestOpens: get(custom, "minecraft:open_chest"),
+        netherPortalEnters: get(custom, "minecraft:enter_nether_portal"),
+        endPortalEnters: get(custom, "minecraft:enter_end_portal"),
+
+        villagerTrades: get(custom, "minecraft:traded_with_villager"),
+        fishCaught: get(custom, "minecraft:fish_caught"),
+        animalsBred: get(custom, "minecraft:animals_bred"),
+
+        advancements: adv.advancements,
+        recipesUnlocked: adv.recipes,
+      });
+
+      void TICKS_PER_SECOND;
+    } catch {
+      // skip corrupt
+    }
+  }
+
+  out.sort((a, b) => b.playtimeHours - a.playtimeHours);
+  return out;
+}
+
+function round2(n: number): number {
+  return Math.round(n * 100) / 100;
+}