chore: add .gitignore, remove build artifacts from tracking

.gitignore

@@ -0,0 +1,4 @@
+.build/
+build/
+*.xcodeproj
+.DS_Store

Package.swift

@@ -8,7 +8,7 @@ let package = Package(
         .macOS(.v14)
     ],
     products: [
-        .library(name: "MiniPlayer", targets: ["MiniPlayer"])
+        .executable(name: "MiniPlayer", targets: ["MiniPlayer"])
     ],
     dependencies: [
         .package(path: "../SwiftBricks")
@@ -18,7 +18,7 @@ let package = Package(
             name: "MiniPlayer",
             dependencies: ["SwiftBricks"],
             resources: [
-                .copy("Resources")
+                .process("Resources")
             ]
         )
     ]

Sources/MiniPlayerApp.swift

@@ -47,8 +47,8 @@ struct ContentView: View {
     
     var body: some View {
         Group {
-            if let engine = bridge.engine {
-                BricksView(schema: bridge.schema!, engine: engine)
+            if let engine = bridge.engine, let schema = bridge.schema {
+                BricksView(schema: schema, engine: engine)
                     .overlay(alignment: .top) {
                         if let error = bridge.toastMessage {
                             Text(error)