Rewrite all UI tests following fail-fast TEST_RULES patterns

Rewrote 60+ test files to follow honeydue-style test guidelines:
- defaultTimeout=2s, navigationTimeout=5s — fail fast, no long waits
- No coordinate taps (except onboarding paged TabView swipes)
- No sleep(), no retry loops
- No guard...else { return } silent passes — XCTFail everywhere
- All elements by accessibility ID via UITestID constants
- Screen objects for all navigation/actions/assertions
- One logical assertion per test method

Added missing accessibility identifiers to app views:
- MonthView.swift: added AccessibilityID.MonthView.grid to ScrollView
- YearView.swift: added AccessibilityID.YearView.heatmap to ScrollView

Framework rewrites:
- BaseUITestCase: added session ID, localeArguments, extraLaunchArguments
- WaitHelpers: waitForExistenceOrFail, waitUntilHittableOrFail,
  waitForNonExistence, scrollIntoView, forceTap
- All 7 screen objects rewritten with fail-fast semantics
- TEST_RULES.md added with non-negotiable rules

Known remaining issues:
- OnboardingTests: paged TabView swipes unreliable on iOS 26 simulator
- SettingsLegalLinksTests: EULA/Privacy buttons too deep in DEBUG scroll
- Customization horizontal picker scrolling needs further tuning

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Tests iOS/AppResumeTests.swift

@@ -10,25 +10,25 @@ import XCTest
 final class AppResumeTests: BaseUITestCase {
     override var seedFixture: String? { "week_of_moods" }
 
-    /// TC-153: Force quit and relaunch — app resumes with data intact.
-    func testAppResumes_FromBackground() {
-        // Verify initial state
+    /// TC-153: Force quit and relaunch -- tab bar visible and data intact.
+    func testAppResumes_TabBarVisible() {
         let tabBar = TabBarScreen(app: app)
-        tabBar.assertTabBarVisible()
-        assertDayContentVisible()
+        tabBar.assertVisible()
 
-        captureScreenshot(name: "before_background")
-
-        // Relaunch preserving state (simulates background + foreground)
         relaunchPreservingState()
 
-        // Tab bar should be visible again
         let freshTabBar = TabBarScreen(app: app)
-        freshTabBar.assertTabBarVisible()
+        freshTabBar.assertVisible()
+    }
 
-        // Day content should still be visible (data persisted)
-        assertDayContentVisible()
+    /// TC-153b: Force quit and relaunch -- seeded entry data still present.
+    func testAppResumes_DataIntact() {
+        let dayScreen = DayScreen(app: app)
+        dayScreen.assertAnyEntryExists()
 
-        captureScreenshot(name: "after_resume")
+        relaunchPreservingState()
+
+        let freshDayScreen = DayScreen(app: app)
+        freshDayScreen.assertAnyEntryExists()
     }
 }