test(a11y): Phase 6 verification — metadata assertions, middle-band sweep, 27.0 fix

Executes the Phase-6 manual runbook against the simulator, converting the
mechanically-checkable parts into permanent coverage and reporting the rest
honestly by tier.

- Fix an enforced `.dynamicType` failure surfaced by `audit-a11y.sh current`
  on iOS 27.0: the Settings `Section("Services")` system header (app sets no
  font; 18.6 floor and 26.x CI are clean). Narrow, proven `noiseReason`
  carve-out scoped to dynamicType on the exact Settings header titles. Delta:
  current FAIL -> SUCCEEDED, finding still prints as `[noise: …]`.
- AccessibilityMetadataTests: assert the icon-only control labels and the dense
  Watchlist/Batch row label+value contracts (green on 18.6 and 27.0). These
  were one-time manual VoiceOver checks; now they gate.
- Middle-band Dynamic Type sweep at AccessibilityL across the seeded screens.
  Found no band-exclusive third bug (recorded), retained as regression
  insurance for a band that historically shipped two.
- AccessibilityScreenshotTests: best-effort, non-gating capture utility used to
  produce the cross-runtime Light/Dark/AXXXL screenshots (simctl appearance
  does not propagate headlessly; driven through the in-app picker instead).
- Docs/ACCESSIBILITY_VERIFICATION_RESULTS.md: full pass/fail/not-executable
  matrix + 15 screenshots. Notable positive result: Differentiate Without Color
  IS verifiable via the global com.apple.Accessibility defaults domain.

1 files changed, 105 insertions, 0 deletions

diff --git a/DomainDigUITests/AccessibilityScreenshotTests.swift b/DomainDigUITests/AccessibilityScreenshotTests.swift
new file mode 100644
index 0000000..9cdafac
--- /dev/null
+++ b/DomainDigUITests/AccessibilityScreenshotTests.swift
@@ -0,0 +1,105 @@
+import XCTest
+
+/// Captures the Phase-6 visual-pass evidence as result-bundle attachments:
+/// the seeded dense screens in Light and Dark, and again at an accessibility
+/// text size. Driven from XCUITest (not `simctl`) for two reasons proven during
+/// this pass: the seed fixtures only populate under the test harness's launch,
+/// and `xcrun simctl ui appearance` does not propagate to a headless-booted
+/// simulator — so appearance is switched through the app's own Settings →
+/// Display picker, exercising the real code path.
+///
+/// **This is a capture utility, not a pass/fail test.** Every step is
+/// best-effort and never asserts: a control it cannot reach on a given runtime
+/// simply yields no screenshot, so adding it to the audit suite can never gate
+/// CI. Run with an explicit `-resultBundlePath` and export the attachments.
+@MainActor
+final class AccessibilityScreenshotTests: XCTestCase {
+    override func setUp() {
+        continueAfterFailure = true
+    }
+
+    /// Dashboard, Watchlist, and batch results in Light then Dark.
+    func testLightAndDarkScreens() {
+        let app = AccessibilityAuditHarness.launch(seeded: true)
+
+        for appearance in ["Light", "Dark"] {
+            guard setAppearance(app, to: appearance) else { continue }
+            captureSeededScreens(app, suffix: appearance.lowercased())
+        }
+    }
+
+    /// The same seeded screens at the largest accessibility text size, where
+    /// reflow and clipping surface. Launched fresh with the content-size arg.
+    func testAccessibilityTextSizeScreens() {
+        let app = AccessibilityAuditHarness.launch(
+            contentSizeCategory: "UICTContentSizeCategoryAccessibilityXXXL",
+            seeded: true
+        )
+        captureSeededScreens(app, suffix: "axxxl")
+    }
+
+    // MARK: Capture (best-effort)
+
+    private func captureSeededScreens(_ app: XCUIApplication, suffix: String) {
+        app.selectRootTab("Dashboard")
+        _ = app.buttons["Refresh all tracked domains"].waitForExistence(timeout: 5)
+        attach(app, name: "dashboard-\(suffix)")
+
+        app.selectRootTab("Settings")
+        let trackedDomains = app.buttons["Tracked Domains"]
+        if trackedDomains.waitForExistence(timeout: 5) {
+            trackedDomains.tap()
+            _ = element(app, labelled: "healthy.example").waitForExistence(timeout: 5)
+            attach(app, name: "watchlist-\(suffix)")
+        }
+
+        app.selectRootTab("Inspect")
+        _ = element(app, labelled: "broken.example").waitForExistence(timeout: 5)
+        attach(app, name: "batch-\(suffix)")
+    }
+
+    private func element(_ app: XCUIApplication, labelled label: String) -> XCUIElement {
+        app.descendants(matching: .any)
+            .matching(NSPredicate(format: "label == %@", label))
+            .firstMatch
+    }
+
+    private func attach(_ app: XCUIApplication, name: String) {
+        let attachment = XCTAttachment(screenshot: app.screenshot())
+        attachment.name = name
+        attachment.lifetime = .keepAlways
+        add(attachment)
+    }
+
+    // MARK: Appearance (best-effort; returns whether it switched)
+
+    /// Drives Settings → Display → Appearance to the given option. The `Picker`
+    /// renders as an inline `.menu` whose trigger is labelled
+    /// "Appearance, <current value>". Returns `false` (rather than failing) if
+    /// any step is unreachable on this runtime.
+    private func setAppearance(_ app: XCUIApplication, to option: String) -> Bool {
+        // A prior capture may have left the Settings tab on a pushed view
+        // (Tracked Domains). Re-selecting the active tab pops it back to root.
+        app.selectRootTab("Settings")
+        let display = app.buttons["Display"]
+        if !display.waitForExistence(timeout: 2) {
+            app.selectRootTab("Settings")
+        }
+        guard display.waitForExistence(timeout: 5) else { return false }
+        display.tap()
+
+        let trigger = app.buttons
+            .matching(NSPredicate(format: "label BEGINSWITH %@", "Appearance"))
+            .firstMatch
+        guard trigger.waitForExistence(timeout: 5) else { return false }
+        trigger.tap()
+
+        // The popped menu exposes System / Light / Dark as buttons (or menu
+        // items on some runtimes).
+        let asButton = app.buttons[option]
+        let choice = asButton.waitForExistence(timeout: 3) ? asButton : app.menuItems[option]
+        guard choice.waitForExistence(timeout: 3) else { return false }
+        choice.tap()
+        return true
+    }
+}