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/Screens/SettingsScreen.swift

@@ -0,0 +1,44 @@
+//
+//  SettingsScreen.swift
+//  PlantGuideUITests
+//
+//  Screen object for the Settings tab.
+//
+
+import XCTest
+
+struct SettingsScreen {
+    let app: XCUIApplication
+
+    // MARK: - Elements
+
+    var navigationBar: XCUIElement { app.navigationBars["Settings"] }
+
+    var notificationsToggle: XCUIElement {
+        app.switches[UITestID.Settings.notificationsToggle]
+    }
+
+    var clearCacheButton: XCUIElement {
+        app.buttons[UITestID.Settings.clearCacheButton]
+    }
+
+    var versionInfo: XCUIElement {
+        app.staticTexts[UITestID.Settings.versionInfo]
+    }
+
+    /// The settings form container — SwiftUI Form renders as a table or collection view.
+    var formContainer: XCUIElement {
+        if app.tables.firstMatch.waitForExistence(timeout: 3) {
+            return app.tables.firstMatch
+        } else {
+            return app.collectionViews.firstMatch
+        }
+    }
+
+    // MARK: - State Checks
+
+    @discardableResult
+    func waitForLoad(timeout: TimeInterval = 10) -> Bool {
+        navigationBar.waitForExistence(timeout: timeout)
+    }
+}