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/unicode.test.mjs

@@ -0,0 +1,108 @@
+// unicode.test.mjs — Integration tests for the unicode-scanner
+// Tests against the evil-project-health fixture which contains:
+//   - Zero-width characters in SKILL.fixture.md
+//   - Unicode Tag block codepoints (steganographic hidden message) in SKILL.fixture.md
+//   - BIDI override characters in SKILL.fixture.md
+
+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/unicode-scanner.mjs';
+
+const __dirname = fileURLToPath(new URL('.', import.meta.url));
+const FIXTURE = resolve(__dirname, '../../examples/malicious-skill-demo/evil-project-health');
+
+describe('unicode-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 zero-width characters (CRITICAL or HIGH)', async () => {
+    const result = await scan(FIXTURE, discovery);
+    const zeroWidthFindings = result.findings.filter(f =>
+      (f.severity === 'critical' || f.severity === 'high') &&
+      (
+        f.title.toLowerCase().includes('zero-width') ||
+        f.title.toLowerCase().includes('zero width') ||
+        (f.evidence && f.evidence.toLowerCase().includes('u+200'))
+      )
+    );
+    assert.ok(
+      zeroWidthFindings.length >= 1,
+      `Expected at least 1 zero-width finding, got ${zeroWidthFindings.length}. ` +
+      `All findings: ${result.findings.map(f => f.title).join('; ')}`
+    );
+  });
+
+  it('detects Unicode Tag block codepoints (CRITICAL) — steganographic hidden message', async () => {
+    const result = await scan(FIXTURE, discovery);
+    const tagFindings = result.findings.filter(f =>
+      f.severity === 'critical' &&
+      f.title.toLowerCase().includes('unicode tag')
+    );
+    assert.ok(
+      tagFindings.length >= 1,
+      `Expected at least 1 Unicode Tag finding (CRITICAL), got ${tagFindings.length}. ` +
+      `All findings: ${result.findings.map(f => f.title).join('; ')}`
+    );
+  });
+
+  it('reports at least 3 total findings across all categories', async () => {
+    const result = await scan(FIXTURE, discovery);
+    assert.ok(
+      result.findings.length >= 3,
+      `Expected >= 3 total unicode findings, got ${result.findings.length}`
+    );
+  });
+
+  it('assigns correct scanner prefix UNI to all findings', async () => {
+    const result = await scan(FIXTURE, discovery);
+    const wrongPrefix = result.findings.filter(f => !f.id.startsWith('DS-UNI-'));
+    assert.equal(
+      wrongPrefix.length, 0,
+      `All findings should have DS-UNI- prefix. Wrong: ${wrongPrefix.map(f => f.id).join(', ')}`
+    );
+  });
+
+  it('finding IDs are sequential starting from DS-UNI-001', async () => {
+    const result = await scan(FIXTURE, discovery);
+    if (result.findings.length === 0) return;
+    assert.equal(result.findings[0].id, 'DS-UNI-001');
+  });
+
+  it('all findings have required fields', async () => {
+    const result = await scan(FIXTURE, discovery);
+    for (const f of result.findings) {
+      assert.ok(f.id, `Finding missing id`);
+      assert.ok(f.scanner, `Finding ${f.id} missing scanner`);
+      assert.ok(f.severity, `Finding ${f.id} missing severity`);
+      assert.ok(f.title, `Finding ${f.id} missing title`);
+      assert.ok(f.owasp, `Finding ${f.id} missing owasp`);
+    }
+  });
+
+  it('counts object reflects actual findings array', async () => {
+    const result = await scan(FIXTURE, discovery);
+    const countTotal = Object.values(result.counts).reduce((s, n) => s + n, 0);
+    assert.equal(
+      countTotal, result.findings.length,
+      `counts total (${countTotal}) should equal findings.length (${result.findings.length})`
+    );
+  });
+});