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/wv2installer/download.go

@@ -0,0 +1,35 @@
+//go:build windows && !wv2runtime.error && !wv2runtime.browser && !wv2runtime.embed
+// +build windows,!wv2runtime.error,!wv2runtime.browser,!wv2runtime.embed
+
+package wv2installer
+
+import (
+	"fmt"
+
+	"github.com/wailsapp/wails/v2/internal/webview2runtime"
+	"github.com/wailsapp/wails/v2/pkg/options/windows"
+)
+
+func doInstallationStrategy(installStatus installationStatus, messages *windows.Messages) error {
+	message := messages.InstallationRequired
+	if installStatus == needsUpdating {
+		message = messages.UpdateRequired
+	}
+	confirmed, err := webview2runtime.Confirm(message, messages.MissingRequirements)
+	if err != nil {
+		return err
+	}
+	if !confirmed {
+		return fmt.Errorf(messages.Webview2NotInstalled)
+	}
+	installedCorrectly, err := webview2runtime.InstallUsingBootstrapper()
+	if err != nil {
+		_ = webview2runtime.Error(err.Error(), messages.Error)
+		return err
+	}
+	if !installedCorrectly {
+		err = webview2runtime.Error(messages.FailedToInstall, messages.Error)
+		return err
+	}
+	return nil
+}