Switch remote deploy to vendored source builds

Move remote deployment to a vendored source bundle built on the target host via Docker so redeploys no longer require local cross-compilation or host Go installation.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

vendor/github.com/wailsapp/wails/v2/internal/webview2runtime/webview2installer.go

@@ -0,0 +1,21 @@
+package webview2runtime
+
+import (
+	_ "embed"
+	"os"
+	"path/filepath"
+)
+
+//go:embed MicrosoftEdgeWebview2Setup.exe
+var setupexe []byte
+
+// WriteInstallerToFile writes the installer file to the given file.
+func WriteInstallerToFile(targetFile string) error {
+	return os.WriteFile(targetFile, setupexe, 0o755)
+}
+
+// WriteInstaller writes the installer exe file to the given directory and returns the path to it.
+func WriteInstaller(targetPath string) (string, error) {
+	installer := filepath.Join(targetPath, `MicrosoftEdgeWebview2Setup.exe`)
+	return installer, WriteInstallerToFile(installer)
+}