feat(llm-security): sandboxed remote cloning v5.1.0

Harden git clone attack surface for remote scans with defense-in-depth:

Layer 1 (all platforms): 8 git config flags disable hooks, symlinks,
filter/smudge drivers, fsmonitor, local file protocol. 4 env vars
isolate from system/user git config and block interactive prompts.

Layer 2 (OS sandbox): macOS sandbox-exec and Linux bubblewrap (bwrap)
restrict file writes to only the specific temp directory. bwrap
probe-tests availability before use. Graceful fallback on Windows
and Ubuntu 24.04+ (git config hardening only).

Additional: post-clone 100MB size check, UUID-unique evidence filenames,
evidence file cleanup, cleanup guarantee in scan/plugin-audit commands.

32 new tests (1147 total).

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

plugins/llm-security/package.json

@@ -1,6 +1,6 @@
 {
   "name": "llm-security",
-  "version": "5.0.0",
+  "version": "5.1.0",
   "description": "Security scanning, auditing, and threat modeling for Claude Code projects",
   "type": "module",
   "engines": {