feat(llm-security): add /security ide-scan — VS Code / JetBrains extension prescan (v6.3.0)

New standalone scanner (prefix IDE) discovers installed VS Code extensions
across forks (Cursor, Windsurf, VSCodium, code-server, Insiders, Remote-SSH)
and runs 7 IDE-specific threat checks: blocklist match (CRITICAL),
theme-with-code, sideload (unsigned .vsix), dangerous uninstall hook (HIGH),
wildcard activation, extension-pack expansion, typosquat (MEDIUM).

Per-extension reuse of UNI/ENT/NET/TNT/MEM/SCR scanners with bounded
concurrency. Offline-first; --online opt-in. JetBrains discovery stubbed
for v1.1. 22 new tests (1296 total, was 1274).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/llm-security/scanners/lib/ide-extension-data.mjs

@@ -0,0 +1,69 @@
+// ide-extension-data.mjs — Loads top-extensions + blocklist from knowledge files.
+// Zero dependencies (Node.js builtins only).
+// Used by ide-extension-scanner.mjs for typosquat + blocklist checks.
+
+import { readFile } from 'node:fs/promises';
+import { join, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const KNOWLEDGE_DIR = join(__dirname, '..', '..', 'knowledge');
+
+let _vscode = null;
+let _jetbrains = null;
+
+async function loadJson(path) {
+  try {
+    const raw = await readFile(path, 'utf8');
+    return JSON.parse(raw);
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * Load top VS Code extension IDs.
+ * @returns {Promise<string[]>} Lowercased "publisher.name" strings.
+ */
+export async function loadTopVSCode() {
+  if (_vscode !== null) return _vscode.vscode || [];
+  _vscode = await loadJson(join(KNOWLEDGE_DIR, 'top-vscode-extensions.json')) || { vscode: [], blocklist: [] };
+  return (_vscode.vscode || []).map(normalizeId);
+}
+
+/**
+ * Load VS Code extension blocklist entries.
+ * @returns {Promise<string[]>} Entries of form "publisher.name@version" or "publisher.name@*".
+ */
+export async function loadVSCodeBlocklist() {
+  if (_vscode !== null) return _vscode.blocklist || [];
+  _vscode = await loadJson(join(KNOWLEDGE_DIR, 'top-vscode-extensions.json')) || { vscode: [], blocklist: [] };
+  return _vscode.blocklist || [];
+}
+
+/**
+ * Load top JetBrains plugin IDs (stub for v1.1).
+ * @returns {Promise<string[]>}
+ */
+export async function loadTopJetBrains() {
+  if (_jetbrains !== null) return _jetbrains.jetbrains || [];
+  _jetbrains = await loadJson(join(KNOWLEDGE_DIR, 'top-jetbrains-plugins.json')) || { jetbrains: [], blocklist: [] };
+  return (_jetbrains.jetbrains || []).map(normalizeId);
+}
+
+/**
+ * Normalize extension ID for comparison.
+ * @param {string} id
+ * @returns {string}
+ */
+export function normalizeId(id) {
+  return String(id || '').toLowerCase().trim();
+}
+
+/**
+ * Reset cache (for tests).
+ */
+export function _resetCache() {
+  _vscode = null;
+  _jetbrains = null;
+}