SiYuan: Path Traversal via Double URL Encoding in `/export/` Endpoint (Incomplete Fix Bypass for CVE-2026-30869)

Summary The fix for CVE-2026-30869 in SiYuan v3.5.10 only added a denylist check IsSensitivePath but did not address the root cause — a redundant url.PathUnescape call in serveExport. An authenticated attacker can use double URL encoding %252e%252e to traverse directories and read arbitrary...