Add native Crystal exploration port and reference tooling

scripts/check-reference.mjs

@@ -0,0 +1,63 @@
+import { createHash } from "node:crypto";
+import { readFileSync } from "node:fs";
+import { execFileSync } from "node:child_process";
+
+const root = ".reference/pokecrystal";
+const expected = "f2f52230b536214ef7c9924f483392993e226cfb";
+const romPath =
+  process.env.CRYSTAL_ROM_PATH ??
+  "Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc";
+const supplied = readFileSync(romPath),
+  rebuilt = readFileSync(`${root}/pokecrystal11.gbc`);
+if (
+  createHash("sha1").update(supplied).digest("hex") !== expected ||
+  !supplied.equals(rebuilt)
+)
+  throw new Error(
+    "The supplied ROM and reference rebuild must exactly match revision 1.1.",
+  );
+const revision = execFileSync("git", ["-C", root, "rev-parse", "HEAD"], {
+  encoding: "utf8",
+}).trim();
+if (revision !== "7a7881d0d62e0ddbd82dcf10e7116807487ac651")
+  throw new Error("Unexpected PRET revision.");
+const symbols = new Map(
+  readFileSync(`${root}/pokecrystal11.sym`, "utf8")
+    .split("\n")
+    .flatMap((line) => {
+      const match = /^([0-9a-f]{2}):([0-9a-f]{4}) (\S+)$/.exec(line);
+      if (!match) return [];
+      const bank = parseInt(match[1], 16),
+        address = parseInt(match[2], 16);
+      return [
+        [
+          match[3],
+          address < 0x4000 ? address : bank * 0x4000 + address - 0x4000,
+        ],
+      ];
+    }),
+);
+const names = {
+  mapGroups: "MapGroupPointers",
+  tilesets: "Tilesets",
+  collisions: "CollisionPermissionTable",
+  environmentColors: "EnvironmentColorsPointers",
+  backgroundPalettes: "TilesetBGPalette",
+  objectPalettes: "MapObjectPals",
+  roofPalettes: "RoofPals",
+  roofTypes: "MapGroupRoofs",
+  roofs: "Roofs",
+  housePalettes: "HousePalette",
+  sprites: "OverworldSprites",
+  facings: "Facings",
+  standardScripts: "StdScripts",
+};
+const profile = readFileSync("src/game/rom/profile.ts", "utf8");
+for (const [key, symbol] of Object.entries(names)) {
+  const match = new RegExp(`${key}:\\s*(0x[0-9a-f]+)`, "i").exec(profile);
+  if (!match || Number(match[1]) !== symbols.get(symbol))
+    throw new Error(`Profile address mismatch: ${key} / ${symbol}`);
+}
+console.log(
+  "User ROM, pinned PRET rebuild and all native profile addresses match.",
+);