bc985f8857
Makes the N-file array-write case usable as the real-controller hardware gate: AB_LEGACY_ARRAY_WRITE_BASE names the first of six consecutive words (default N7:1), each word is read first and written back in a finally, and the neighbours are verified per word with coalescing off. Live-run green on ab_server slc500/micrologix/plc5 x libplctag/native (39/39), and with a moved base (N7:3). Refs #738 Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT