deps: update esbuild to 0.27.4, rollup to 4.60.0, vite to 7.3.1
- bump esbuild and all platform-specific binaries from 0.25.10 to 0.27.4
- bump rollup and all platform-specific binaries from 4.52.3 to 4.60.0
- bump vite from 7.1.7 to 7.3.1 (esbuild peer dep updated to ^0.27.0)
- bump dompurify from 3.2.7 to 3.3.3
web: improve cover image retry logic
- increase maxRetries default from 3 to 5
- reduce initial retryDelay from 1000ms to 500ms
- implement exponential backoff: delay = retryDelay * 2^(retryCount - 1)
- add detailed logging for retries and final failure
rust: minor cleanup
- remove unused imports (watch, Url, AudioSegment, SyncMarker)
- add tracing debug logs for cache file requests
- handle missing files gracefully with warning + client retry hint
- add #[allow(async_fn_in_trait)] where needed
