fix(security): enforce plugin and hook path containment

src/security/scan-paths.ts

@@ -1,3 +1,4 @@
+import fs from "node:fs";
 import path from "node:path";
 
 export function isPathInside(basePath: string, candidatePath: string): boolean {
@@ -7,6 +8,30 @@ export function isPathInside(basePath: string, candidatePath: string): boolean {
   return rel === "" || (!rel.startsWith(`..${path.sep}`) && rel !== ".." && !path.isAbsolute(rel));
 }
 
+function safeRealpathSync(filePath: string): string | null {
+  try {
+    return fs.realpathSync(filePath);
+  } catch {
+    return null;
+  }
+}
+
+export function isPathInsideWithRealpath(
+  basePath: string,
+  candidatePath: string,
+  opts?: { requireRealpath?: boolean },
+): boolean {
+  if (!isPathInside(basePath, candidatePath)) {
+    return false;
+  }
+  const baseReal = safeRealpathSync(basePath);
+  const candidateReal = safeRealpathSync(candidatePath);
+  if (!baseReal || !candidateReal) {
+    return opts?.requireRealpath !== true;
+  }
+  return isPathInside(baseReal, candidateReal);
+}
+
 export function extensionUsesSkippedScannerPath(entry: string): boolean {
   const segments = entry.split(/[\\/]+/).filter(Boolean);
   return segments.some(