v0.1.1

Other

• Fix issues found reviewing the new hotplug and isochronous code
• Test that two sessions can watch hotplug at the same time
• Simplify the netlink drain loop
• Assert the Windows structure layouts at compile time
• Document the hotplug feature and the Windows isochronous packet rules
• Add Windows and macOS hotplug backends, and Windows isochronous transfers
• Add optional hotplug notifications with a Linux netlink backend
• Make hardware tests tolerate synthesised root hubs
• Write README and changelog for the initial release
• Add macOS backend (IOKit IOUSBLib, CFRunLoop event thread)
• Add Windows backend (SetupAPI/CfgMgr enumeration, hub ioctls, WinUSB + IOCP)
• Add hardware tests and list_devices example
• Add core API and Linux usbfs backend
• Fix config descriptor test fixture attributes

Added

• Core API: Context, Device, DeviceHandle, Transfer with synchronous
  helpers and the asynchronous submit/cancel/wait/callback/Future layer.
• Descriptor parsing (device, configuration tree, interface associations,
  SuperSpeed companions, string descriptors, BOS retrieval).
• Linux backend (sysfs + usbfs) with bulk URB splitting, isochronous
  transfers, timeouts, cancellation, disconnect handling and kernel-driver
  detach/attach.
• Windows backend (SetupAPI/CfgMgr enumeration, hub ioctls for descriptors,
  WinUSB transfers on an I/O completion port, composite-function support).
• macOS backend (IOKit IOUSBLib device/interface objects, CFRunLoop event
  thread, kernel-side timeouts on the 182 interface revisions).
• Optional hotplug feature: Context::hotplug() builds a filtered watcher
  that reports devices arriving and leaving, either through a callback or a
  queue, with enumerate_existing for a race-free start. Backed by netlink
  uevents on Linux, CM_Register_Notification on Windows and IOKit matching
  notifications on macOS.
• Isochronous transfers on Windows, through the WinUSB isoch API (Windows
  8.1 and newer), including per-packet results for IN transfers and seamless
  stream continuation while transfers stay queued on an endpoint.
• list_devices and hotplug examples, and a self-skipping hardware test
  suite.