Implement new Go based Desktop app

This focuses on Windows first, but coudl be used for Mac
and possibly linux in the future.

cmd/start_darwin.go

@@ -0,0 +1,30 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/jmorganca/ollama/api"
+)
+
+func startApp(ctx context.Context, client *api.Client) error {
+	exe, err := os.Executable()
+	if err != nil {
+		return err
+	}
+	link, err := os.Readlink(exe)
+	if err != nil {
+		return err
+	}
+	if !strings.Contains(link, "Ollama.app") {
+		return fmt.Errorf("could not find ollama app")
+	}
+	path := strings.Split(link, "Ollama.app")
+	if err := exec.Command("/usr/bin/open", "-a", path[0]+"Ollama.app").Run(); err != nil {
+		return err
+	}
+	return waitForServer(ctx, client)
+}