Replace the Go backend with the Rust workspace and route Android/iOS through
UniFFI bindings. Include the migrated extension runtime, network, providers,
media metadata, downloads and library operations, with version 5.0.0+147.
Remove Go sources, adapters, native build selection and CI dependencies.
Build Rust unconditionally and lock the iOS Rust pod using a relative path.
Retain legacy source and migration evidence in a local ignored archive.
Validation: Android Kotlin compile and 53 native tests; Swift Rust-branch
equivalence and syntax; CocoaPods install; workflow, shell, Ruby, plist and
diff checks. Reuse the preceding 100 Rust tests, fmt/Clippy and five-ABI
build checkpoint; no new APK or iOS application build for this cleanup.
Known follow-up: URL/URLSearchParams globals are missing from the Rust JS
runtime. A controlled extension replay confirms a URL-resolution regression;
this commit does not fix that runtime gap.
The download API only permits one request at a time, so parallel
downloads are removed to avoid wasted/blocked API calls. Downloads
now always run sequentially (one track at a time).
- Drop concurrentDownloads from AppSettings + JSON serialization
- Remove setConcurrentDownloads and the settings UI (1-5 chips + warning)
- Strip optionsConcurrent* l10n keys from all ARBs and regenerate
- Rework queue worker into _processQueueSequential (single active download)
- Update marketing copy and adjust tests
Audio Analysis Enhancements:
- Display codec name and container format
- Show decoded sample format (s16, s32, fltp, etc.)
- Add LUFS integrated loudness measurement (broadcast standard)
- Add true peak measurement (dBTP)
- Detect and count clipping samples per channel
- Estimate spectral cutoff frequency (helps detect fake upscales)
- Show per-channel statistics (Peak, RMS, DR, Clip count)
UI Improvements:
- MetricChip now handles long text with ellipsis
- Constrained max width for better layout
Cache version bumped to 4 to force rescan with new metrics.