Refresh the Flutter snapshot: v3 tickets V3-04 through V3-16, plus a fresh installable APK

V3-04 through V3-07, V3-10, V3-16 shipped complete; V3-11/V3-12/V3-14 shipped code-complete pending device/account verification; V3-08/V3-09 deferred behind a new V3-17 (self-hosted OSRM investigation). 316 tests passing, up from 221.

The APK is a fresh release build (debug-signed, no release signing config exists yet) with two build fixes applied: core library desugaring enabled for flutter_local_notifications, and sentry_flutter bumped to 9.27.0 (8.14.2's bundled Kotlin plugin was incompatible with this project's Kotlin 2.4.0 toolchain).

rippr-flutter-src/test/theme_test.dart

@@ -0,0 +1,82 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:rippr/src/ui/theme.dart';
+
+/// V3-16's acceptance criterion is "contrast ratios meet WCAG AA for body text" --
+/// asserted directly here rather than trusted from a palette chosen by eye. AA is 4.5:1
+/// for normal text, 3:1 for large text (18pt, or 14pt bold and up -- the headline
+/// figures in `BigStat`).
+void main() {
+  group('contrastRatio', () {
+    test('black on white is the maximum possible ratio, 21:1', () {
+      expect(
+        contrastRatio(const Color(0xFF000000), const Color(0xFFFFFFFF)),
+        closeTo(21.0, 0.01),
+      );
+    });
+
+    test('a colour against itself is 1:1', () {
+      const c = Color(0xFFFF5722);
+      expect(contrastRatio(c, c), closeTo(1.0, 0.01));
+    });
+
+    test('is symmetric regardless of argument order', () {
+      const a = Color(0xFF101418);
+      const b = Color(0xFFF2F5F8);
+      expect(contrastRatio(a, b), contrastRatio(b, a));
+    });
+  });
+
+  group('pocketed theme (WCAG AA)', () {
+    final colors = ripprTheme().colorScheme;
+
+    test('body text on the ground meets AA normal text (4.5:1)', () {
+      expect(contrastRatio(colors.onSurface, ripprBackground), greaterThanOrEqualTo(4.5));
+    });
+
+    test('body text on a surface card meets AA normal text (4.5:1)', () {
+      expect(contrastRatio(colors.onSurface, colors.surface), greaterThanOrEqualTo(4.5));
+    });
+
+    test('the primary accent on the ground meets AA large text (3:1)', () {
+      // The accent is used for headline figures and buttons, not small body copy --
+      // held to the large-text threshold, matching how it's actually used on screen.
+      expect(contrastRatio(colors.primary, ripprBackground), greaterThanOrEqualTo(3.0));
+    });
+
+    test('the instrument-blue tertiary on the ground meets AA large text (3:1)', () {
+      expect(contrastRatio(colors.tertiary, ripprBackground), greaterThanOrEqualTo(3.0));
+    });
+
+    test('the instrument-blue tertiary on a surface card meets AA large text (3:1)', () {
+      expect(contrastRatio(colors.tertiary, colors.surface), greaterThanOrEqualTo(3.0));
+    });
+  });
+
+  group('mounted theme (WCAG AA)', () {
+    final colors = ripprMountedTheme().colorScheme;
+
+    test('body text on the ground meets AA normal text (4.5:1)', () {
+      expect(
+        contrastRatio(colors.onSurface, ripprMountedBackground),
+        greaterThanOrEqualTo(4.5),
+      );
+    });
+
+    test('the primary accent on the ground meets AA large text (3:1) -- this is the '
+        'theme sunlight legibility actually depends on', () {
+      expect(
+        contrastRatio(colors.primary, ripprMountedBackground),
+        greaterThanOrEqualTo(3.0),
+      );
+    });
+
+    test('the instrument-blue tertiary meets AA normal text on the ground '
+        '(darkened further than the pocketed theme specifically for this)', () {
+      expect(
+        contrastRatio(colors.tertiary, ripprMountedBackground),
+        greaterThanOrEqualTo(4.5),
+      );
+    });
+  });
+}