test(ios): cover ScreenController webview setup

apps/ios/Tests/ScreenControllerTests.swift

@@ -0,0 +1,28 @@
+import Testing
+import WebKit
+@testable import Clawdis
+
+@Suite struct ScreenControllerTests {
+    @Test @MainActor func canvasModeConfiguresWebViewForTouch() {
+        let screen = ScreenController()
+
+        #expect(screen.mode == .canvas)
+        #expect(screen.webView.isOpaque == false)
+        #expect(screen.webView.backgroundColor == .clear)
+
+        let scrollView = screen.webView.scrollView
+        #expect(scrollView.backgroundColor == .clear)
+        #expect(scrollView.contentInsetAdjustmentBehavior == .never)
+        #expect(scrollView.isScrollEnabled == false)
+        #expect(scrollView.bounces == false)
+    }
+
+    @Test @MainActor func webModeRejectsInvalidURLStrings() {
+        let screen = ScreenController()
+        screen.navigate(to: "   \n")
+        screen.setMode(.web)
+
+        #expect(screen.mode == .web)
+    }
+}
+