Two strands of in-progress work, committed together because they overlap
in sras_workers.py and main_window.py.
Min peak frequency floor:
- CACH tail bumped to version 4, adding u32 min_freq_khz provenance in
fixed-point kHz (a float32 20.1 reads back as 20.10000038 and would
report a spurious mismatch forever). v1-v3 tails read as no floor.
- Stored FFT caches are accepted when the reader's floor is at or above
the stored one, since a higher floor is re-applicable by masking.
- Floor plumbed through compute_rf_image, BatchCacheWorker and the viewer.
Batch Export View as Images:
- New sras_render.py holds draw_view_image, shared by the Qt canvas and
the headless exporter so a PNG cannot drift from what the GUI shows.
Deliberately Qt-free so it is importable in a pool subprocess.
- BatchExportImagesWorker renders the current view settings across many
files, process-pooled with an inline fallback, reporting per-file
output names so the caller can flag same-stem collisions.
- _axes_extent extracted into sras_format for both render paths.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Thomas Ales [M S E]