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/Screens/NoteEditorScreen.swift

@@ -10,54 +10,61 @@ import XCTest
 struct NoteEditorScreen {
     let app: XCUIApplication
 
+    private let defaultTimeout: TimeInterval = 2
+    private let navigationTimeout: TimeInterval = 5
+
     // MARK: - Elements
 
-    var navigationTitle: XCUIElement { app.navigationBars.firstMatch }
     var textEditor: XCUIElement { app.textViews[UITestID.NoteEditor.text] }
     var saveButton: XCUIElement { app.buttons[UITestID.NoteEditor.save] }
     var cancelButton: XCUIElement { app.buttons[UITestID.NoteEditor.cancel] }
 
     // MARK: - Actions
 
-    func typeNote(_ text: String) {
-        textEditor.tapWhenReady()
+    @discardableResult
+    func typeNote(_ text: String, file: StaticString = #filePath, line: UInt = #line) -> NoteEditorScreen {
+        textEditor
+            .waitUntilHittableOrFail(timeout: defaultTimeout, message: "Note text editor should be hittable", file: file, line: line)
+            .tap()
         textEditor.typeText(text)
+        return self
     }
 
-    func clearAndTypeNote(_ text: String) {
-        textEditor.tapWhenReady()
-        // Select all and replace
+    @discardableResult
+    func clearAndTypeNote(_ text: String, file: StaticString = #filePath, line: UInt = #line) -> NoteEditorScreen {
+        textEditor
+            .waitUntilHittableOrFail(timeout: defaultTimeout, message: "Note text editor should be hittable", file: file, line: line)
+            .tap()
         textEditor.press(forDuration: 1.0)
         let selectAll = app.menuItems["Select All"]
-        if selectAll.waitForExistence(timeout: 2) {
+        if selectAll.waitForExistence(timeout: defaultTimeout) {
             selectAll.tap()
         }
         textEditor.typeText(text)
+        return self
     }
 
-    func save() {
-        saveButton.tapWhenReady()
+    func save(file: StaticString = #filePath, line: UInt = #line) {
+        saveButton
+            .waitUntilHittableOrFail(timeout: defaultTimeout, message: "Save button should be hittable", file: file, line: line)
+            .forceTap(file: file, line: line)
     }
 
-    func cancel() {
-        cancelButton.tapWhenReady()
+    func cancel(file: StaticString = #filePath, line: UInt = #line) {
+        cancelButton
+            .waitUntilHittableOrFail(timeout: defaultTimeout, message: "Cancel button should be hittable", file: file, line: line)
+            .forceTap(file: file, line: line)
     }
 
     // MARK: - Assertions
 
-    func assertVisible(file: StaticString = #file, line: UInt = #line) {
-        XCTAssertTrue(
-            textEditor.waitForExistence(timeout: 5),
-            "Note editor should be visible",
-            file: file, line: line
-        )
+    @discardableResult
+    func assertVisible(file: StaticString = #filePath, line: UInt = #line) -> NoteEditorScreen {
+        textEditor.waitForExistenceOrFail(timeout: navigationTimeout, message: "Note editor should be visible", file: file, line: line)
+        return self
     }
 
-    func assertDismissed(file: StaticString = #file, line: UInt = #line) {
-        XCTAssertTrue(
-            textEditor.waitForDisappearance(timeout: 5),
-            "Note editor should be dismissed",
-            file: file, line: line
-        )
+    func assertDismissed(file: StaticString = #filePath, line: UInt = #line) {
+        textEditor.waitForNonExistence(timeout: navigationTimeout, message: "Note editor should be dismissed", file: file, line: line)
     }
 }