Refactor Qobuz bundle fetching to improve resilience and performance. Add HTTP timeout and retry configuration, and implement a retry loop that returns version metadata. Introduce bundle version caching and persistence to skip redundant extractions when the bundle remains unchanged. Replace console logging with structured tracing macros and update the architectural tracking document to mark these improvements as complete.
Introduce a `/tracks/:id/flac` endpoint and `open_cmaf_stream` client method to enable incremental decryption and caching of FLAC audio. Refactor segment decryption into a reusable helper and stream decrypted frames via a bounded tokio channel. Add `tokio-util` as an optional dependency, update the `pmoserver` feature, and implement conditional routing for local proxy versus direct API access. Update the architecture roadmap to document these improvements.
Introduces a new CMAF streaming module for Qobuz that handles progressive segment fetching and full-track decryption. The implementation adds HKDF session key derivation, AES-128-CBC key unwrapping, and AES-128-CTR frame decryption, alongside an ISO BMFF parser for extracting FLAC headers and segment metadata. It also integrates automatic session renewal with double-checked locking, a generic async retry mechanism for transient HTTP errors, and centralized error handling. Finally, it exposes `CmafStreamInfo` and async streaming methods in the public API, updating cryptographic dependencies accordingly.
