feat(llm-security-copilot): port llm-security v5.1.0 to GitHub Copilot CLI

Full port of llm-security plugin for internal use on Windows with GitHub
Copilot CLI. Protocol translation layer (copilot-hook-runner.mjs)
normalizes Copilot camelCase I/O to Claude Code snake_case format — all
original hook scripts run unmodified.

- 8 hooks with protocol translation (stdin/stdout/exit code)
- 18 SKILL.md skills (Agent Skills Open Standard)
- 6 .agent.md agent definitions
- 20 scanners + 14 scanner lib modules (unchanged)
- 14 knowledge files (unchanged)
- 39 test files including copilot-port-verify.mjs (17 tests)
- Windows-ready: node:path, os.tmpdir(), process.execPath, no bash

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins/llm-security-copilot/tests/scanners/entropy.test.mjs

@@ -0,0 +1,98 @@
+// entropy.test.mjs — Integration tests for the entropy-scanner
+// Tests against the evil-project-health fixture which contains:
+//   - ENCODED_CONFIG: base64 blob in SKILL.fixture.md
+//   - auth_credential: high-entropy hardcoded credential in telemetry.mjs
+
+import { describe, it, beforeEach } from 'node:test';
+import assert from 'node:assert/strict';
+import { resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { resetCounter } from '../../scanners/lib/output.mjs';
+import { discoverFiles } from '../../scanners/lib/file-discovery.mjs';
+import { scan } from '../../scanners/entropy-scanner.mjs';
+
+const __dirname = fileURLToPath(new URL('.', import.meta.url));
+const FIXTURE = resolve(__dirname, '../../examples/malicious-skill-demo/evil-project-health');
+
+describe('entropy-scanner integration', () => {
+  let discovery;
+
+  beforeEach(async () => {
+    resetCounter();
+    discovery = await discoverFiles(FIXTURE);
+  });
+
+  it('returns status ok', async () => {
+    const result = await scan(FIXTURE, discovery);
+    assert.equal(result.status, 'ok', `Expected status 'ok', got '${result.status}'`);
+  });
+
+  it('scans at least one file', async () => {
+    const result = await scan(FIXTURE, discovery);
+    assert.ok(result.files_scanned >= 1, `Expected files_scanned >= 1, got ${result.files_scanned}`);
+  });
+
+  it('detects at least 1 high-entropy string (base64 payload in telemetry.mjs)', async () => {
+    // The scanner suppresses fixture/ and test/ paths, so only telemetry.mjs is live-scanned.
+    // The base64 ENCODED_CONFIG (len=84, H≈5.18) triggers a HIGH finding.
+    // The auth_credential (len=32) is below the 40-char MEDIUM minimum length threshold.
+    const result = await scan(FIXTURE, discovery);
+    assert.ok(
+      result.findings.length >= 1,
+      `Expected >= 1 high-entropy finding, got ${result.findings.length}. ` +
+      `Findings: ${result.findings.map(f => `${f.file}:${f.line} ${f.evidence}`).join('; ')}`
+    );
+  });
+
+  it('reports findings with HIGH or CRITICAL severity', async () => {
+    const result = await scan(FIXTURE, discovery);
+    const highOrCritical = result.findings.filter(
+      f => f.severity === 'high' || f.severity === 'critical'
+    );
+    assert.ok(
+      highOrCritical.length >= 1,
+      `Expected at least 1 HIGH or CRITICAL entropy finding, got ${highOrCritical.length}`
+    );
+  });
+
+  it('assigns correct scanner prefix ENT to all findings', async () => {
+    const result = await scan(FIXTURE, discovery);
+    const wrongPrefix = result.findings.filter(f => !f.id.startsWith('DS-ENT-'));
+    assert.equal(
+      wrongPrefix.length, 0,
+      `All findings should have DS-ENT- prefix. Wrong: ${wrongPrefix.map(f => f.id).join(', ')}`
+    );
+  });
+
+  it('finding IDs are sequential starting from DS-ENT-001 after reset', async () => {
+    const result = await scan(FIXTURE, discovery);
+    if (result.findings.length === 0) return;
+    assert.equal(result.findings[0].id, 'DS-ENT-001');
+  });
+
+  it('all findings include entropy value in evidence', async () => {
+    const result = await scan(FIXTURE, discovery);
+    for (const f of result.findings) {
+      assert.ok(
+        f.evidence && f.evidence.includes('H='),
+        `Finding ${f.id} evidence should include H= entropy value, got: ${f.evidence}`
+      );
+    }
+  });
+
+  it('all findings map to LLM01 or LLM03 owasp category', async () => {
+    const result = await scan(FIXTURE, discovery);
+    for (const f of result.findings) {
+      assert.ok(
+        f.owasp === 'LLM01' || f.owasp === 'LLM03',
+        `Finding ${f.id} owasp should be LLM01 or LLM03, got: ${f.owasp}`
+      );
+    }
+  });
+
+  it('duration_ms is a non-negative number', async () => {
+    const result = await scan(FIXTURE, discovery);
+    assert.ok(typeof result.duration_ms === 'number', 'duration_ms should be a number');
+    assert.ok(result.duration_ms >= 0, 'duration_ms should be >= 0');
+  });
+});