- Remove deprecated `cocoa` crate in favor of direct `objc` usage to fix future-incompatibilities warning from `block` dependency.
- Fix irrefutable `if let` pattern warning in macOS `SleepPreventer::Drop`.
- Fix memory leaks by properly releasing `alloc`-ed `NSString` and `NSAppleScript` objects.
- Fix AppKit thread safety by routing dock badge updates to the main thread via `run_on_main_thread`.
This commit replaces the frontend-imperative download dispatcher with a centralized backend `QueueManager`. It acts as the sole concurrency gatekeeper using a single `tokio::sync::Semaphore` across all download paths (aria2 RPC, native HTTP, yt-dlp media).
Backend Changes:
- **queue**: Added `QueueManager` to manage an ordered `VecDeque` of tasks, semaphore permits, and retirement debt (CAS resize).
- **commands**: Replaced direct start commands with `enqueue_download`, `enqueue_many`, `move_in_queue`, and `remove_from_queue`.
- **ipc**: Exported `DownloadStateEvent` and `QueueDirection` to the frontend.
- **tests**: Added 11 integration tests covering idle-parking, idempotent releases, CAS underflow prevention, and gid-completion races.
Frontend Changes:
- **store**: Made `useDownloadStore` reactive to the backend via the `download-state` event.
- **store**: Removed `processQueue` and introduced `pendingOrder` to track the accurate sequence of queued items.
- **ui**: Updated `DownloadItem` with queue visuals (clock icon, position badge).
- **ui**: Added Move Up/Down controls to interact with the backend queue reordering API.
- Replace tokio::process with tauri_plugin_shell sidecar API for native cross-compilation bundle execution.
- Implement non-blocking stdout/stderr multiplexing in yt-dlp spawn to prevent OS pipe buffer deadlocks.
- Refactor capabilities to restrict execution explicitly to sidecars instead of wildcards.
- Rename local binaries to strictly adhere to target-triple architecture suffixes.
- Drop manual get_binary_name path resolutions in favor of Tauri's externalBin bundler.
- Fix state corruption on deleted queues in frontend
- Prevent concurrent dispatch of duplicate downloads
- Fix file paths when deleting native downloads
- Ensure pausing and resuming items persist state to database
- Remove duplicate IPC invocations for speed limits
- Stop PropertiesModal from resetting inputs during download progress
- Switch aria2 secret to use secure v4 UUID
- Fix SSRF vulnerability in fetch_metadata via DNS rebinding block
- Resolve race condition when reading media download logs
- Gracefully handle panics when acquiring prevent sleep lock
- Rate limit native downloads respecting global settings
- Enforce TLS certificate validation in backend requests