卫戍协议：盟约 web remake — initial import

Online co-op browser remake of Arknights' Stronghold Protocol: Alliance
(client-simulated combat, official waves/bonds/items/strategies, 3D board,
facing wheel, operator loadout, official emotes, deployment scripts).

server/sim/nodeData.js

@@ -0,0 +1,64 @@
+// server/sim/nodeData.js — the Node-only default data loader of the simulation (DESIGN §14).
+//
+// server/sim/** is shared with browsers (served read-only at /sim/), so every Node API lives here. simdata.js imports
+// this module dynamically — and only under Node — to build its default DataSource:
+//   * generated data: `server/data.js → getData()` (data/*.json, tools/build-data.mjs),
+//   * research fallback: docs/research/03-operators.json, 05-enemies.json, 05-maps.json (sim tests before/without data).
+// Browsers never load this file: they inject the fetched /data/*.json with simdata.js setSimData(data).
+//
+// This module must not import simdata.js (simdata awaits this module at its top level; a cycle would deadlock).
+
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+/** Repository root. */
+export const ROOT = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..', '..');
+
+const QUIET = Object.freeze({ warn() {}, error() {}, info() {} });
+
+/** data/*.json through the server/data.js singleton (null when unavailable). */
+export async function loadGenerated() {
+  try {
+    const mod = await import('../data.js');
+    return mod.getData({ log: QUIET });
+  } catch {
+    return null;
+  }
+}
+
+/** Drop the server/data.js singleton, then load again (tests / hot reload after data regeneration). */
+export async function reloadGenerated() {
+  try {
+    const mod = await import('../data.js');
+    mod.resetData?.();
+  } catch { /* ignore */ }
+  return loadGenerated();
+}
+
+/**
+ * Research JSON in the raw-map shape a DataSource accepts: `{ chess, enemies, tokens, stages, waves }` (tokens carry
+ * `byOwner[chessId]` variants; stages get the research legend).
+ */
+export function loadResearch() {
+  const read = (f) => {
+    try { return JSON.parse(fs.readFileSync(path.join(ROOT, 'docs', 'research', f), 'utf8')); } catch { return null; }
+  };
+  const ops = read('03-operators.json');
+  const en = read('05-enemies.json');
+  const maps = read('05-maps.json');
+  const chess = {};
+  const tokens = {};
+  for (const c of ops?.chess ?? []) {
+    chess[c.chessId] = c;
+    for (const t of c.tokens ?? []) {
+      if (!tokens[t.tokenId]) tokens[t.tokenId] = { ...t, byOwner: {} };
+      tokens[t.tokenId].byOwner[c.chessId] = t;
+    }
+  }
+  const stages = {};
+  for (const [id, s] of Object.entries(maps?.stages ?? {})) {
+    stages[id] = { ...s, legend: maps?._meta?.legend ?? null };
+  }
+  return { chess, enemies: en?.enemies ?? {}, tokens, stages, waves: maps?.roundLevels ?? {} };
+}