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/skills/plugin-audit/SKILL.md

@@ -0,0 +1,57 @@
+---
+name: security-plugin-audit
+description: Audit a plugin for security risks, permission analysis, and trust assessment before installation
+---
+
+# Plugin Audit
+
+Dedicated plugin security audit with trust verdict. Accepts local paths or repository URLs.
+
+## Step 1: Resolve Target
+
+- If `$ARGUMENTS` starts with `https://` → clone the repo:
+  ```bash
+  node <plugin-root>/scanners/lib/git-clone.mjs clone "<url>" [--branch <branch>]
+  ```
+  Set `clone_path` and `target`.
+- Otherwise → `target = $ARGUMENTS` or current directory
+
+## IMPORTANT: Cleanup Guarantee (remote)
+
+If cloned, cleanup MUST run regardless of outcome:
+```bash
+node <plugin-root>/scanners/lib/git-clone.mjs cleanup "<clone_path>"
+```
+
+## Step 2: Pre-extraction (remote only)
+
+```bash
+node <plugin-root>/scanners/lib/fs-utils.mjs tmppath "plugin-extract.json"
+node <plugin-root>/scanners/content-extractor.mjs "<target>" --output-file "<evidence_file>"
+```
+
+## Step 3: Inventory
+
+Read plugin manifest (plugin.json). Glob for all components: commands, agents, hooks, skills, MCP configs. Build permission matrix: what tools each component can access.
+
+## Step 4: Security Analysis
+
+Read `<plugin-root>/knowledge/skill-threat-patterns.md` and `<plugin-root>/knowledge/secrets-patterns.md`.
+
+Analyze all files for 7 threat categories. If remote, analyze from evidence package (never read untrusted files directly). Check hook registration vs scripts (ghost hooks). Cross-reference description vs tools permissions.
+
+## Step 5: Report
+
+Output: Plugin metadata, component inventory, permission matrix, hook analysis, all findings by severity.
+
+**Trust Verdict:**
+- **Install** — No critical or high findings, permissions appropriate
+- **Review** — High findings present but potentially justified, manual review recommended
+- **Do Not Install** — Critical findings, active exfiltration, or injection detected
+
+## Step 6: Cleanup
+
+```bash
+node <plugin-root>/scanners/lib/git-clone.mjs cleanup "<clone_path>"
+node <plugin-root>/scanners/lib/fs-utils.mjs cleanup "<evidence_file>"
+```