[andre487]

IPv6 literals were rejected by Android validation, JSON import and native configuration parsing before connections were attempted. Valid bare/bracketed addresses now work for proxy and jump hosts; native bootstrap normalizes brackets and URL export emits IPv6 authorities correctly. Bootstrap prefers A across resolvers, then tries AAAA only when no A succeeds and at least one valid NODATA response exists. DNS/HTTP errors alone do not trigger fallback.

Coverage includes:

• JVM/editor/import tests for all six proxy types, malformed addresses and URL/JSON round trips.
• Real GOST/OpenSSH IPv4/IPv6 proxy, jump and TCP destination combinations; SOCKS5 UDP; negative authentication controls against direct bypass.
• A controlled MASQUE relay forwarding to a real IPv6 UDP origin.
• API 26/35 TUN/JNI scenarios with IPv4 and IPv6 proxy/jump endpoints and IPv6 destinations, including bracketed input through Android bootstrap.
• A/AAAA preference, invalid responses, cancellation and use of a resolved IPv6 address.

The disposable OpenSSH fixture disables timed source penalties to keep negative authentication cases independent. Device fixtures block direct origin traffic for both address families and wait for the calling UID's VPN default network before sending traffic.

Validation: CI run 479 passed: 360 native tests, 81 real-server integration tests, Android JVM/lint/build checks and both API 26/35 suites. Python tests/style passed on the unchanged ancestor. Only report publication was rerun after GitHub Check API 404 responses; failed tests were not retried.

Limits: GOST 3.3.0 still rejects IPv6 literal CONNECT-UDP, which tests require to fail without direct fallback. The production client has no GOST-specific IPv6 ban and succeeds with the controlled compatible relay. Bootstrap DoH endpoints still require IPv4 reachability; physical IPv6-only uplinks and the reporter's Pixel/GrapheneOS device were not tested.

Fixes #146.