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/InsightsCollapseTests.swift

@@ -11,48 +11,43 @@ final class InsightsCollapseTests: BaseUITestCase {
     override var seedFixture: String? { "week_of_moods" }
     override var bypassSubscription: Bool { true }
 
-    /// TC-046: Tapping a section header collapses/expands that section.
-    func testInsights_CollapseExpandSections() {
+    /// TC-046: Tapping the month section header collapses it.
+    func testInsights_CollapseMonthSection() {
         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_initial")
-
-        // Find the "This Month" section header text and tap to collapse
-        // Note: the text is inside a Button, so we use coordinate tap fallback
-        let monthTitle = app.staticTexts["This Month"].firstMatch
-        XCTAssertTrue(
-            monthTitle.waitForExistence(timeout: 5),
-            "This Month section title should exist"
+        // Tap the month section to collapse it
+        let monthSection = app.element(UITestID.Insights.monthSection)
+        monthSection.waitUntilHittableOrFail(
+            timeout: navigationTimeout,
+            message: "Month section should be hittable"
         )
-
-        monthTitle.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5)).tap()
-
-        // Brief wait for animation
-        _ = app.waitForExistence(timeout: 1)
+        monthSection.forceTap()
 
         captureScreenshot(name: "insights_month_collapsed")
+    }
 
-        // Tap again to expand
-        monthTitle.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5)).tap()
+    /// TC-046b: Tapping the year section header collapses it.
+    func testInsights_CollapseYearSection() {
+        let tabBar = TabBarScreen(app: app)
+        tabBar.tapInsights()
 
-        _ = app.waitForExistence(timeout: 1)
+        let header = app.element(UITestID.Insights.header)
+        header.waitForExistenceOrFail(
+            timeout: navigationTimeout,
+            message: "Insights header should be visible"
+        )
 
-        captureScreenshot(name: "insights_month_expanded")
+        let yearSection = app.element(UITestID.Insights.yearSection)
+        yearSection.scrollIntoView(in: app)
+        yearSection.forceTap()
 
-        // Also test "This Year" section
-        let yearTitle = app.staticTexts["This Year"].firstMatch
-        if yearTitle.waitForExistence(timeout: 3) {
-            yearTitle.coordinate(withNormalizedOffset: CGVector(dx: 0.5, dy: 0.5)).tap()
-            _ = app.waitForExistence(timeout: 1)
-            captureScreenshot(name: "insights_year_collapsed")
-        }
+        captureScreenshot(name: "insights_year_collapsed")
     }
 }