…r MSVC compatibility

Windows test binary crashes immediately (exit code 7, no output) when
Qt platform plugins are unavailable in CI. Linux already had this env
var. Adding it to Windows ensures consistent headless test execution.

… crash

QTemporaryFile appears to cause a CRT initialization crash (exit code 7)
on Windows MSVC with Qt 5.15.2. Replace with direct QFile writes which
is what the original installcli.cpp used successfully. The atomic write
improvement (temp + rename) is not worth a platform-specific crash.

- Add scripts/macos-pkg/postinstall that creates /usr/local/bin/traktor
  symlink during installation (runs as root, no auth dialog needed)
- CI now builds a PKG installer alongside the .app tar for PR testing
- PKG installs Traktor.app to /Applications and creates CLI symlink
- Ad-hoc signed (no Developer ID cert yet) — works for local testing

After uploading release assets, the release workflow now:
1. Computes SHA256 of the macOS DMG
2. Clones servmask/homebrew-traktor
3. Updates Casks/traktor.rb with new version + SHA256
4. Commits and pushes

Requires HOMEBREW_TAP_TOKEN secret with repo write access to
servmask/homebrew-traktor, or falls back to the default GITHUB_TOKEN
(works if both repos are in the same org).

- distribution.xml sets product title to "Traktor" (fixes empty "" in
  trash dialog and generic "Welcome to the Installer" header)
- welcome.html: describes what Traktor does and what the installer will
  set up (app + CLI tool)
- conclusion.html: shows next steps after installation (open app, CLI
  usage examples, MCP registration command)
- Both support dark mode via prefers-color-scheme media query
- Uses productbuild --distribution instead of --package for custom UI

…lling to /Applications

--root with cp -R was not preserving the .app bundle structure in the
PKG payload. --component is the correct pkgbuild flag for bundling
macOS .app directories and sets the install location properly.

The distribution.xml pkg-ref must use #filename.pkg (with # prefix)
to embed the component package inside the product archive. Without it,
productbuild creates an external reference and the payload is empty.
Also adds debug output to verify app bundle and package sizes.

…tions

pkgbuild --component adds a <relocate> directive by default, causing
macOS Installer to search for an existing Traktor.app bundle anywhere
on the system and install there instead of /Applications. If the user
has a build directory with Traktor.app, the installer silently
overwrites it instead of installing to /Applications.

Fix: use --component-plist with BundleIsRelocatable=false to force
installation to the specified --install-location.

…nent plist

Heredoc with XML content inside YAML run block causes GitHub Actions
parser to fail. Use pkgbuild --analyze to auto-generate the component
plist, then PlistBuddy to set BundleIsRelocatable=false.

…sn't support plist)

- Remove DMG from release pipeline (PKG is the sole macOS distribution)
- release.yml: builds PKG, uploads PKG, submits PKG to VirusTotal,
  auto-updates Homebrew Cask from PKG SHA256
- README: add CLI usage, MCP integration, Homebrew install, PKG as
  primary macOS download. Remove DMG references.
- CLAUDE.md: update test count (97), document new source files
  (clihandler, mcpserver, agentconfig, installcli, setupdialog),
  PKG scripts, and updated CI/release process