Release 0.1.3 - Headless API and bug fixes!

• Headless mode with a scriptable HTTP/JSON API (Windows + macOS). Launch
  App Sandbox with --headless to run a single-owner background daemon exposing
  a loopback HTTP/JSON API that mirrors the GUI: create, start, shut down, edit,
  and delete VMs; manage snapshots, branches, and templates (Windows); read SSH
  connection info; subscribe to a live event stream; and open or close a VM's
  display window -- all from a script. Ships a dependency-free Python SDK,
  runnable examples, and a cross-platform test suite (bundled in the release
  package under headless-api/, alongside the app). Launching via GUI is unchanged.

• One-click SSH key login. With the SSH server enabled, the new "Deploy SSH
  key" option installs an App Sandbox key into the guest (Windows, Linux, and
  macOS) so the GUI's SSH button and the SDK connect without a password.

• Excessive GPU usage while viewing a Windows VM. The display window was
  redrawing as fast as it could -- presenting ~2,100 frames a second and holding
  the host GPU near 90% even on a static screen. It now redraws only when the
  picture changes (plus a small safety refresh), dropping to the real frame rate
  (~30-60 fps) with no added latency.

• macOS: text fields no longer autocorrect or autocapitalize VM names,
  usernames, paths, and snapshot names as you type.

• x64 (emulated) apps in ARM Windows VMs don't get the OpenGL fix -- the
  Mesa driver shipped on ARM is ARM64-only; native ARM64 apps get full GPU
  OpenGL. (carried over from 0.1.2)

• ARM Linux (Ubuntu 26.04 LTS) guests do not work -- on ARM, Windows is the
  only working guest (Ubuntu 26.04's arm64 kernel churns BPF JIT memory and
  never reaches the desktop). (carried over from 0.1.2)