MLX - dynamic loading of mlx-c (#13735)

* MLX - dynamic loading of mlx-c

Create a wrapper layer to indirect the dependency on mlx-c so
the main ollama binary does not have a load-time dependency on mlx-c, mlx, and on linux, cuda.  Lazy load the library via dlopen
so we can adjust the path to ensure the dependencies are found
and fail gracefully if not present.

* review comments

* fix broken tests

x/imagegen/models/qwen_image_edit/rope_test.go

@@ -3,13 +3,35 @@
 package qwen_image_edit
 
 import (
+	"fmt"
 	"math"
+	"os"
+	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/ollama/ollama/x/imagegen/mlx"
 	"github.com/ollama/ollama/x/imagegen/models/qwen_image"
 )
 
+// TestMain initializes MLX before running tests.
+// If MLX libraries are not available, tests are skipped.
+func TestMain(m *testing.M) {
+	// Change to repo root so ./build/lib/ollama/ path works
+	_, thisFile, _, _ := runtime.Caller(0)
+	repoRoot := filepath.Join(filepath.Dir(thisFile), "..", "..", "..", "..")
+	if err := os.Chdir(repoRoot); err != nil {
+		fmt.Printf("Failed to change to repo root: %v\n", err)
+		os.Exit(1)
+	}
+
+	if err := mlx.InitMLX(); err != nil {
+		fmt.Printf("Skipping qwen_image_edit tests: %v\n", err)
+		os.Exit(0)
+	}
+	os.Exit(m.Run())
+}
+
 // TestComputeAxisFreqs verifies frequency computation matches Python reference
 func TestComputeAxisFreqs(t *testing.T) {
 	theta := float64(10000)