feat: vision properly coverd with tests and completed

MLXServerTests/Server/TestImageFixtures.swift

@@ -0,0 +1,30 @@
+import Foundation
+
+enum TestImageFixtures {
+    private static let repoRoot: URL = {
+        URL(fileURLWithPath: #filePath)
+            .deletingLastPathComponent()
+            .deletingLastPathComponent()
+            .deletingLastPathComponent()
+    }()
+
+    private static func loadBase64(named name: String) -> String {
+        let url = repoRoot
+            .appendingPathComponent("MLXServer")
+            .appendingPathComponent("Assets.xcassets")
+            .appendingPathComponent("AppIcon.appiconset")
+            .appendingPathComponent(name)
+
+        guard let data = try? Data(contentsOf: url) else {
+            fatalError("Missing image fixture at \(url.path)")
+        }
+
+        return data.base64EncodedString()
+    }
+
+    static let primaryPNGBase64 = loadBase64(named: "icon_16x16.png")
+    static let alternatePNGBase64 = loadBase64(named: "icon_32x32.png")
+
+    static let primaryDataURI = "data:image/png;base64,\(primaryPNGBase64)"
+    static let alternateDataURI = "data:image/png;base64,\(alternatePNGBase64)"
+}