v3.0.1 — activation_fps field, README rename announcement

Added

• AnalysisResult.activation_fps — the frame rate (Hz) of the activations array, populated whenever activations are requested, so downstream consumers can map activation frame indices to timestamps (#2). Backward compatible: older saved JSONs load with None.

Documentation

• Official rename announcement (all-in-one-fix → all-in-one-infer) now front and center in the README; stale allin1 imports in current-usage examples fixed; obsolete NATTEN-required claims replaced with the pure-PyTorch reality; opt-in performance flags documented in CLI and Python API sections.