feat(game): add neon isometric relay interface

tests/levels.test.mjs

@@ -0,0 +1,48 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+
+import { LEVELS, canReachTarget } from '../levels.js';
+import { parseLevel } from '../game-engine.js';
+
+test('every authored relay has reachable signal pads before any echo is anchored', () => {
+  for (const definition of LEVELS) {
+    const level = parseLevel(definition.map);
+    for (const [padId, position] of level.pads) {
+      assert.equal(
+        canReachTarget(level, position, new Set()),
+        true,
+        `${definition.id}: pad ${padId} should be initially reachable`,
+      );
+    }
+  }
+});
+
+test('each relay keeps extraction sealed until its full gate sequence is sustained', () => {
+  for (const definition of LEVELS) {
+    const level = parseLevel(definition.map);
+    const allGates = new Set(level.gates.keys());
+
+    assert.equal(
+      canReachTarget(level, level.goal, new Set()),
+      false,
+      `${definition.id}: extraction must not be reachable with all gates closed`,
+    );
+    assert.equal(
+      canReachTarget(level, level.goal, allGates),
+      true,
+      `${definition.id}: extraction should be reachable with all gates active`,
+    );
+  }
+});
+
+test('multi-gate relays preserve their intended staged locks', () => {
+  const double = parseLevel(LEVELS.find((level) => level.id === 'prism-drift').map);
+  const triple = parseLevel(LEVELS.find((level) => level.id === 'cathedral-null').map);
+
+  assert.equal(canReachTarget(double, double.goal, new Set(['A'])), false);
+  assert.equal(canReachTarget(double, double.goal, new Set(['A', 'B'])), true);
+
+  assert.equal(canReachTarget(triple, triple.goal, new Set(['A'])), false);
+  assert.equal(canReachTarget(triple, triple.goal, new Set(['A', 'B'])), false);
+  assert.equal(canReachTarget(triple, triple.goal, new Set(['A', 'B', 'C'])), true);
+});

tests/shell.test.mjs

@@ -0,0 +1,22 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+
+const root = new URL('../', import.meta.url);
+const readProjectFile = (name) => readFileSync(new URL(name, root), 'utf8');
+
+test('the playable shell uses a local canvas entry point and no external runtime assets', () => {
+  const html = readProjectFile('index.html');
+
+  assert.match(html, /<canvas[^>]+id="relay-canvas"/);
+  assert.match(html, /<script\s+type="module"\s+src="\.\/app\.js"><\/script>/);
+  assert.match(html, /data-action="anchor"/);
+  assert.doesNotMatch(html, /<(?:script|link|img)\b[^>]+(?:src|href)\s*=\s*["']https?:\/\//i);
+});
+
+test('the runtime exposes a narrow smoke-test surface without network calls', () => {
+  const app = readProjectFile('app.js');
+
+  assert.match(app, /window\.__VANTA_TEST__/);
+  assert.doesNotMatch(app, /\bfetch\s*\(|XMLHttpRequest|WebSocket/);
+});