Build Windows installer with Velopack instead of WiX

vpk runs on the machine's modern .NET runtime (WiX 3.11's .NET Framework
shim fails under the SYSTEM account) and produces a per-user Setup.exe
that needs no runtime on end-user machines.

scripts/release.py

@@ -67,14 +67,14 @@ def load_token() -> str:
 # ZIP + dist helpers
 # ---------------------------------------------------------------------------
 
-# Matches MediaHive-1.2.3-win64.zip, MediaHive-1.2.3-win64.msi,
+# Matches MediaHive-1.2.3-win64.zip, MediaHive-1.2.3-win64-setup.exe,
 # MediaHive-1.2.3-macos-arm64.dmg, etc.
 # Rejects dev/dirty versions like MediaHive-1.2.3.dev0+gabcd-win64.zip
-_CLEAN_ARTIFACT_RE = re.compile(r"^MediaHive-(\d+(?:\.\d+)*)-([A-Za-z0-9._-]+)\.(?:zip|dmg|msi)$")
+_CLEAN_ARTIFACT_RE = re.compile(r"^MediaHive-(\d+(?:\.\d+)*)-([A-Za-z0-9._-]+)\.(?:zip|dmg|exe)$")
 
 
 def find_releasable_artifacts() -> list[tuple[Path, str, str]]:
-    """Return (path, version, platform_tag) for clean-versioned ZIPs/DMGs/MSIs in build/."""
+    """Return (path, version, platform_tag) for clean-versioned ZIPs/DMGs/EXEs in build/."""
     build_dir = REPO_ROOT / "build"
     results = []
     for p in sorted(build_dir.glob("MediaHive-*")):
@@ -184,7 +184,6 @@ def upload_asset(
     mime = {
         ".zip": "application/zip",
         ".dmg": "application/x-apple-diskimage",
-        ".msi": "application/x-msi",
     }.get(path.suffix, "application/octet-stream")
     print(f"Uploading {path.name} ({size_mb:.1f} MB) ...")
     with Path(path).open("rb") as fh:
@@ -230,7 +229,7 @@ def main() -> None:
         artifacts = find_releasable_artifacts()
         if not artifacts:
             print(
-                "No clean-versioned ZIPs/DMGs/MSIs found in build/.\n"
+                "No clean-versioned ZIPs/DMGs/EXEs found in build/.\n"
                 "Run scripts/guibuild.py first.",
                 file=sys.stderr,
             )