The Convert Audio tool promised configurable bitrate, sample rate, and channel count, but only format and bitrate were exposed. Adds an optional sampleRate setting (8000 to 96000 Hz, omitted = preserve source) wired through the Zod schema, the FFmpeg -ar flag, the standalone settings panel, and the pipeline builder controls.
Impossible combinations fail loudly instead of degrading silently: MP3 + 96000 Hz is rejected (libmp3lame caps at 48 kHz), and MP3 bitrates above the encoder ceiling at low rates (64 kbps at 8 kHz, 160 kbps at 16/22.05 kHz) are rejected rather than clamped. The UI offers only legal combinations and sanitizes stored pipeline settings on load.
Docs updated in English plus all 20 localized pages with refreshed i18n_source_hash stamps; two new UI strings added to all 21 locales.
Fixes#558
Move all fixture files from flat/mixed dirs (content/, media/, documents/,
formats/, hostile/, root loose) into the modality-first hierarchy:
image/{valid,formats,edge,hostile}, video/{valid,formats,hostile},
audio/{valid,formats,hostile}, document/{valid,formats,edge,hostile},
data/valid/, security/. Update index.ts paths, fixtureDir aliases,
all literal refs in 17 e2e/qa/script files, manifest.json, and the
three generator scripts. 163 files moved, 0 dropped, 100 new tests
from expanded document scan.