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/InsightsPullToRefreshTests.swift

@@ -11,41 +11,28 @@ final class InsightsPullToRefreshTests: BaseUITestCase {
     override var seedFixture: String? { "week_of_moods" }
     override var bypassSubscription: Bool { true }
 
-    /// TC-047: Pull-to-refresh gesture on Insights tab does not crash and UI remains functional.
+    /// TC-047: Pull-to-refresh gesture on Insights tab does not crash.
     func testInsights_PullToRefresh_NoLayoutCrash() {
         let tabBar = TabBarScreen(app: app)
         tabBar.tapInsights()
 
-        // Verify Insights header loads
         let header = app.element(UITestID.Insights.header)
-        XCTAssertTrue(
-            header.waitForExistence(timeout: 8),
-            "Insights header should be visible"
+        header.waitForExistenceOrFail(
+            timeout: navigationTimeout,
+            message: "Insights header should be visible"
         )
 
         captureScreenshot(name: "insights_before_refresh")
 
-        // Perform pull-to-refresh gesture (drag from top area downward)
-        let start = app.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.3))
-        let end = app.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.8))
-        start.press(forDuration: 0.1, thenDragTo: end)
+        // Perform pull-to-refresh gesture
+        app.swipeDown()
 
-        // Wait for refresh to settle
-        _ = app.waitForExistence(timeout: 3)
+        // Verify UI is still functional after refresh
+        header.waitForExistenceOrFail(
+            timeout: navigationTimeout,
+            message: "Insights header should still be visible after pull-to-refresh"
+        )
 
         captureScreenshot(name: "insights_after_refresh")
-
-        // Verify UI is still functional — header should still be there
-        XCTAssertTrue(
-            header.waitForExistence(timeout: 5),
-            "Insights header should still be visible after pull-to-refresh"
-        )
-
-        // Verify sections are still present
-        let monthTitle = app.staticTexts["This Month"].firstMatch
-        XCTAssertTrue(
-            monthTitle.waitForExistence(timeout: 5),
-            "This Month section should still be visible after pull-to-refresh"
-        )
     }
 }