[cppla]

Summary

• Include relay DNS and service-port resolution in the existing client-owned native QUIC dial context and timeout budget. A stalled DNS lookup no longer keeps AutoCAR's physical dial worker alive after client cancellation or its deadline.
• Preserve the standard UDP resolver's address-family preference, mapped IPv6/zones, empty host and service-port behavior. Individual callers still cancel only their wait on a shared attempt; the configured relay hostname still owns certificate verification.
• Add isolated real-loopback DNS cancellation/deadline regressions and a successful named-relay control with a trusted DNS-only certificate, actual authenticated FIN/echo and joined closure. Document the standard-library/OS resolver background-work boundary.

Validation

• The same frozen cancellation fixture failed both intended oracles once on the unchanged base, with independent cleanup; both pass after this fix. No candidate retry was needed.
• Full make check and make race passed using Go 1.27.1.
• Go 1.25.13 focused race/shuffle: exactly 12 top-level tests x10; 500 inclusive RUN/PASS nodes, zero failure/skip/race reports. Includes address compatibility, owned-worker cancellation, successful authenticated native QUIC, shared caller cancellation, reconnect, TLS fallback, and FD controls.
• Actual isolated Linux/arm64 Docker execution: the same 12 top-level tests x3 (150 inclusive RUN/PASS nodes), CGO=0/non-race, no external network, zero failures/skips. Frozen source/input/compiler/binary guards passed; the owned test container was removed.

No dependency, wire protocol, default configuration, tag or release change. These are lifecycle, compatibility and successful-flow checks; they do not assert a browser fingerprint, comparative ranking or performance result. Client Close joins AutoCAR's physical worker, not every standard-library DNS or OS resolver worker.

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