chore: import upstream snapshot with attribution

tests/docs/configure-ecc-install-paths.test.js

@@ -0,0 +1,69 @@
+'use strict';
+
+const assert = require('assert');
+const fs = require('fs');
+const path = require('path');
+
+const repoRoot = path.resolve(__dirname, '..', '..');
+
+const configureEccDocs = [
+  'skills/configure-ecc/SKILL.md',
+  'docs/zh-CN/skills/configure-ecc/SKILL.md',
+  'docs/ja-JP/skills/configure-ecc/SKILL.md',
+];
+
+let passed = 0;
+let failed = 0;
+
+function test(name, fn) {
+  try {
+    fn();
+    console.log(`  ✓ ${name}`);
+    passed++;
+  } catch (error) {
+    console.log(`  ✗ ${name}`);
+    console.log(`    Error: ${error.message}`);
+    failed++;
+  }
+}
+
+function readConfigureEccDoc(relativePath) {
+  return fs.readFileSync(path.join(repoRoot, relativePath), 'utf8');
+}
+
+console.log('\n=== Testing configure-ecc install path guidance ===\n');
+
+for (const relativePath of configureEccDocs) {
+  test(`${relativePath} separates core and niche skill source roots`, () => {
+    const content = readConfigureEccDoc(relativePath);
+
+    assert.ok(
+      content.includes('$ECC_ROOT/.agents/skills/<skill-name>'),
+      'Expected configure-ecc to document the core skill source root'
+    );
+    assert.ok(
+      content.includes('$ECC_ROOT/skills/<skill-name>'),
+      'Expected configure-ecc to document the niche skill source root'
+    );
+  });
+
+  test(`${relativePath} documents defensive copy form for trailing slash sources`, () => {
+    const content = readConfigureEccDoc(relativePath);
+
+    assert.ok(
+      content.includes('${src%/}'),
+      'Expected configure-ecc to strip trailing slash before copying'
+    );
+    assert.ok(
+      content.includes('$(basename "${src%/}")'),
+      'Expected configure-ecc to preserve the skill directory name explicitly'
+    );
+  });
+}
+
+if (failed > 0) {
+  console.log(`\nFailed: ${failed}`);
+  process.exit(1);
+}
+
+console.log(`\nPassed: ${passed}`);