DuckFlight core v0.1.12

Four platform core payloads built from DuckFlight source commit 7f7415f070ca3db2d0ce4cd5d397a404506b20b1 using Rust 1.97.0.

Fixes native DuckDB host termination when a Flight client disconnects during a socket write. Accepted Flight sockets retain TCP_NODELAY and use writes that suppress SIGPIPE locally, preserving the host application's signal handlers.

Each payload passed architecture, exported ABI, dependency and build-path audits, plus an actual ABI load check. The fixed Linux bundle passed all nine native CLI/ADBC tests, including abrupt disconnects, all 43 fixture queries, concurrency, and shutdown/restart.

See SHA256SUMS and the accompanying binary redistribution license. These payloads are embedded into the public DuckDB extension at build time; no runtime download is required.