Rebuild UI test foundation with page objects, wait helpers, and screen objects

Replace brittle localized-string selectors and broken wait helpers with a
robust, identifier-first UI test infrastructure. All 41 UI tests pass on
iOS 26.2 simulator (iPhone 17).

Foundation:
- BaseUITestCase with deterministic launch helpers (launchClean, launchOffline)
- WaitHelpers (waitUntilHittable, waitUntilGone, tapWhenReady) replacing sleep()
- UITestID enum mirroring AccessibilityIdentifiers from the app target
- Screen objects: TabBarScreen, CameraScreen, CollectionScreen, TodayScreen,
  SettingsScreen, PlantDetailScreen

Key fixes:
- Tab navigation uses waitForExistence+tap instead of isHittable (unreliable
  in iOS 26 simulator)
- Tests handle real app state (empty collection, no camera permission)
- Increased timeouts for parallel clone execution
- Added NetworkMonitorProtocol and protocol-typed DI for testability
- Fixed actor-isolation issues in unit test mocks

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

PlantGuideUITests/PlantGuideUITests.swift

@@ -2,40 +2,28 @@
 //  PlantGuideUITests.swift
 //  PlantGuideUITests
 //
-//  Created by Trey Tartt on 1/21/26.
+//  Smoke tests verifying the app launches and basic navigation works.
 //
 
 import XCTest
 
-final class PlantGuideUITests: XCTestCase {
+final class PlantGuideUITests: BaseUITestCase {
 
-    override func setUpWithError() throws {
-        // Put setup code here. This method is called before the invocation of each test method in the class.
-
-        // In UI tests it is usually best to stop immediately when a failure occurs.
-        continueAfterFailure = false
-
-        // In UI tests it’s important to set the initial state - such as interface orientation - required for your tests before they run. The setUp method is a good place to do this.
-    }
-
-    override func tearDownWithError() throws {
-        // Put teardown code here. This method is called after the invocation of each test method in the class.
-    }
+    // MARK: - Smoke Tests
 
     @MainActor
-    func testExample() throws {
-        // UI tests must launch the application that they test.
-        let app = XCUIApplication()
-        app.launch()
-
-        // Use XCTAssert and related functions to verify your tests produce the correct results.
+    func testAppLaunches() throws {
+        launchClean()
+        let tabs = TabBarScreen(app: app)
+        tabs.assertAllTabsExist()
     }
 
     @MainActor
     func testLaunchPerformance() throws {
-        // This measures how long it takes to launch your application.
         measure(metrics: [XCTApplicationLaunchMetric()]) {
-            XCUIApplication().launch()
+            app.launchArguments += [LaunchConfigKey.uiTesting, LaunchConfigKey.skipOnboarding]
+            app.launchEnvironment[LaunchConfigKey.isUITesting] = "YES"
+            app.launch()
         }
     }
 }