Add javascript/ssrf-ipv6-transition-incomplete-guard, an experimental
@kind problem query that flags hand-rolled SSRF host guards which reject
private/loopback IPv4 ranges but never unwrap IPv6-transition forms
(IPv4-mapped ::ffff:, NAT64 64:ff9b::, 6to4 2002::). Such guards can be
bypassed by wrapping an internal IPv4 address in a transition literal.
Includes a .qhelp with good/bad examples, a change note, and a test pack
with two true-positive fixtures (private-ip package guard and a
hand-written RFC 1918 denylist) and two negative-control fixtures
(ipaddr.js range classifier and an explicit ::ffff: unwrap).
Signed-off-by: tonghuaroot <23011166+tonghuaroot@users.noreply.github.com>
