Chrisnov Media Toolkit v0.1.0-beta.5

Added

• Download History tab (app/window.py)
  New 4th tab (📋 History) recording every completed and failed download.
  Persisted to ~/.config/chrisnov-media-toolkit/download-history.json
  with a versioned JSON schema so history survives app restarts.
  Includes search/filter (All / Audio / Video / Playlist), Clear All with
  confirmation, and double-click to Open Folder or Re-download.

Fixed

• Info button vs Start button race (app/window.py)
  Pressing Start while the Info worker was still running spawned two
  yt-dlp instances on the same URL. When an Info result arrived
  mid-download it also clobbered the status label back to "Ready.",
  making the download look stalled. Added _dl_active flag so Info
  disables Start while fetching, and _on_info_result guards its status
  reset behind _dl_active.

• macOS x86_64 build stuck in "queued" (.github/workflows/build-macos.yml)
  The Intel runner label was pinned to macos-13, which GitHub has retired
  — no host backs it anymore, so the x86_64 leg queued indefinitely.
  Updated to macos-15-intel; also pinned the arm64 leg to macos-15
  for reproducible releases.