22b780e075
The 2026-08-09 pin was a DAILY build; BtbN retention aged it out and the cold-cache download 404'd on the creator's first native recording attempt (2026-09-01, startup.log). Re-pinned to the MONTH-END build autobuild-2026-08-31-13-27 (N-126342, lgpl-shared win64 — 2-year retention; tag+variant recorded in TASKS.md per the licensing rule). Verified alive: HEAD 200 + zip contents (bin/ffmpeg.exe, bin/ffprobe.exe, 7 libav DLLs) match the name-agnostic extractor. Also closes the wrap-gap: HttpRequestException escaped the locator untouched, surfacing a raw 'Response status code... 404' from the frame pump; now wrapped in IOException with the refresh-pin-or-install-ffmpeg message. FfmpegLocatorTests 7/7 (one updated, one added for the 404 case).