Restructure step 0: test safety net, AppEvent/Notifier seam, platform ports, protocol 16 planned

- Tests: the four known failures fixed (test-side causes), one duplicate
  file and four detail-pinning cases removed, every test that pins
  behaviour the restructure changes tagged with its step.
- Every toast, sound and activity-log line goes through Notifier.notify
  (AppEvent), mapped one-to-one to today's behaviour.
- Platform ports (shell, URLs, folders, link resolver, system
  notifications) with desktop implementations; window_manager, Process
  and file_picker now live only in platform/desktop/.
- ROADMAP: protocol 16 planned; app id dev.foxyz.starsync.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/desktop/test/coord_presence_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 1 (Connection + Identity + Presence): reconnect,
+// resume and ready restore; "feed and chat toasts" in step 2 (Notifier).
 import 'dart:async';
 import 'dart:io';
 

apps/desktop/test/delivery_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 2 (Status + Notifier): delivery lines become
+// part of the one computed status (and the source-gone half of P2).
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:sync_relay_core/core.dart';

apps/desktop/test/files_page_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 4 (Library + Media identity): series
+// grouping on the page follows L1/L2.
 import 'dart:async';
 import 'dart:io';
 import 'dart:typed_data';

apps/desktop/test/files_scanner_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 4 (Library + Media identity): groupBySeries
+// becomes L1 local grouping; the scan and classify tests stay.
 import 'dart:io';
 
 import 'package:flutter_test/flutter_test.dart';

apps/desktop/test/home_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 3 (Your server): hosted recents and the host
+// card; the rest stays.
 import 'dart:convert';
 import 'dart:io' show Platform;
 

apps/desktop/test/jellyfin_e2e_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 5 (Watch tracking): the progress-reporting
+// checks; the guest-through-the-relay flow stays.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';

apps/desktop/test/jellyfin_session_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 5 (What's next + Watch tracking): the
+// "progress" and "episodes" groups (reporting, auto-advance swapper).
 import 'dart:convert';
 
 import 'package:flutter/gestures.dart';
@@ -364,11 +366,6 @@ void main() {
       expect(media.jellyfin!.subtitle, 'Black Summoner · S1E7');
     });
 
-    test('the floating prompt starts two minutes before the end', () {
-      expect(nextPromptStart(null, const Duration(minutes: 24)), const Duration(minutes: 22));
-      expect(nextPromptStart(null, const Duration(seconds: 90)), Duration.zero);
-    });
-
     test('one auto-advance swapper: the lowest id among members with their own account', () {
       final members = [
         member('m10', 'Ann', jf: {fixtureServerId: true}),

apps/desktop/test/library_tab_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 3 (Your server): the "solo" and "hosting"
+// tests (D9: no solo mode); the rest stays.
 import 'dart:convert';
 
 import 'package:flutter/material.dart';

apps/desktop/test/media_input_test.dart

@@ -1,33 +0,0 @@
-import 'package:flutter_test/flutter_test.dart';
-import 'package:watch_together/src/widgets/media_input.dart';
-
-void main() {
-  test('http url routes to linkUrl', () {
-    expect(parseMediaInput('http://example.com/v.mp4'),
-        (mediaPath: '', linkUrl: 'http://example.com/v.mp4'));
-  });
-
-  test('https url routes to linkUrl', () {
-    expect(parseMediaInput('https://example.com/v.mp4'),
-        (mediaPath: '', linkUrl: 'https://example.com/v.mp4'));
-  });
-
-  test('scheme match is case-insensitive and trimmed', () {
-    expect(parseMediaInput('  HTTPS://example.com/v.mp4  '),
-        (mediaPath: '', linkUrl: 'HTTPS://example.com/v.mp4'));
-  });
-
-  test('file path routes to mediaPath', () {
-    expect(parseMediaInput('/home/u/Videos/chiyo.mp4'),
-        (mediaPath: '/home/u/Videos/chiyo.mp4', linkUrl: ''));
-  });
-
-  test('empty input stays empty', () {
-    expect(parseMediaInput('   '), (mediaPath: '', linkUrl: ''));
-  });
-
-  test('non-http scheme stays a path', () {
-    expect(parseMediaInput('ftp://example.com/v.mp4'),
-        (mediaPath: 'ftp://example.com/v.mp4', linkUrl: ''));
-  });
-}

apps/desktop/test/player_settings_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 3 (Your server): invite addresses (P24) and
+// the hosting invite; the settings cards stay.
 import 'dart:io';
 
 import 'package:flutter/material.dart';

apps/desktop/test/player_status_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 2 (Status + Notifier): the "status" group
+// (one computed level); the title block and overflow checks stay.
 import 'dart:typed_data';
 
 import 'package:flutter/material.dart';
@@ -165,16 +167,6 @@ void main() {
       expect(find.byKey(const ValueKey('now-playing-episode')), findsNothing);
       expect(tester.takeException(), isNull);
     });
-
-    testWidgets('a new media fades through', (tester) async {
-      await tester.pumpWidget(host(const NowPlayingBlock(now: now)));
-      await tester.pumpWidget(host(const NowPlayingBlock(now: NowPlaying(title: 'Dune'))));
-      await tester.pump(const Duration(milliseconds: 60));
-      expect(find.text('Frieren'), findsOneWidget, reason: 'still fading out');
-      await tester.pumpAndSettle();
-      expect(find.text('Frieren'), findsNothing);
-      expect(find.text('Dune'), findsOneWidget);
-    });
   });
 
   testWidgets('start banner: up before playback, fades on play, never back for that media', (tester) async {

apps/desktop/test/queue_logic_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 5 (What's next): who performs an item and
+// the janitor become server state.
 import 'package:flutter_test/flutter_test.dart';
 import 'package:sync_relay_core/core.dart';
 import 'package:watch_together/src/queue/queue_logic.dart';

apps/desktop/test/queue_switch_e2e_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 6 (Media pipeline): preload and the warm
+// relay become one pipeline; keep the timing per source.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';

apps/desktop/test/relay_e2e_test.dart

@@ -1,3 +1,6 @@
+// restructure: rewrite in step 1 (Connection + Identity + Presence): "the
+// source drops uncleanly and resumes" (resume token, D6 source resume); the
+// rest stays.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
@@ -65,6 +68,7 @@ Future<(HttpServer, List<String>)> _origin(String file) async {
 void main() {
   late SyncServer server;
   late List<SessionCoordinator> all;
+  late List<Object> serverErrors;
 
   Future<SessionCoordinator> member(String name) async {
     final acc = JellyfinAccounts(store: MemoryJellyfinStore());
@@ -102,7 +106,15 @@ void main() {
     MediaKit.ensureInitialized();
     all = [];
     server = SyncServer(const AppConfig(port: 0, secret: 'pw', name: 'vps'));
-    await server.start();
+    // Relic reports an error writing a response (a relay read cut short
+    // when its relay is dropped at a swap or at the stop in tearDown) to
+    // the zone the server started in, as it logs it outside tests;
+    // anything else fails the test.
+    serverErrors = [];
+    await runZonedGuarded(server.start, (e, _) {
+      if ('$e'.contains('Content size below specified contentLength') || '$e'.contains('did not arrive')) return;
+      serverErrors.add(e);
+    });
   });
 
   tearDown(() async {
@@ -110,6 +122,7 @@ void main() {
       await x.dispose();
     }
     await server.stop();
+    expect(serverErrors, isEmpty, reason: 'server errors');
   });
 
   test('a guest puts up a file: it plays for everyone through the relay', timeout: const Timeout(Duration(minutes: 2)),
@@ -127,8 +140,9 @@ void main() {
     expect(relay.buffers.single.bytesToViewers, greaterThan(0), reason: 'alice played through the relay');
     expect(relay.sourceToken, bob.sync.token);
 
-    // The next swap retires bob's source and the buffer.
-    alice.swapPicked(const LinkMedia('http://127.0.0.1:1/none.mkv'));
+    // The next swap retires bob's source and the buffer. Nothing answers
+    // at that link, so its probe refuses it unless put up anyway.
+    expect(await alice.swapPicked(const LinkMedia('http://127.0.0.1:1/none.mkv', anyway: true)), isNull);
     await _poll(() => !bob.relaying.peek(), 'source stopped');
     expect(server.hub.relay, isNull);
   });
@@ -155,7 +169,8 @@ void main() {
       await playTogether([alice, bob]);
       expect(hits.length, greaterThan(before));
 
-      // A page yt-dlp cannot read is refused up front.
+      // A page is refused up front when this computer cannot read it (here
+      // yt-dlp is off, and the refusal says so).
       final page = await HttpServer.bind(InternetAddress.loopbackIPv4, 0);
       page.listen((r) {
         r.response.headers.contentType = ContentType.html;
@@ -163,7 +178,7 @@ void main() {
         r.response.close();
       });
       expect(await alice.swapPicked(LinkMedia('http://127.0.0.1:${page.port}/watch?v=x', relay: LinkRelay.me)),
-          contains('Not a video'));
+          'yt-dlp is turned off');
       await page.close(force: true);
     } finally {
       await origin.close(force: true);

apps/desktop/test/schedule_page_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 3 (Your server): "solo: the button says
+// Play"; the rest stays.
 import 'dart:convert';
 import 'dart:io';
 

apps/desktop/test/server_isolate_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 3 (Your server): one hub with listeners
+// attached, nothing restarts, no solo mode.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';

apps/desktop/test/session_logic_test.dart

@@ -1,3 +1,6 @@
+// restructure: rewrite in step 1 (Connection + Identity + Presence):
+// IdleTracker and unreadyForNewMedia give way to auto sit-out;
+// linkDisplayName stays.
 import 'package:flutter_test/flutter_test.dart';
 import 'package:watch_together/src/session/idle.dart';
 import 'package:watch_together/src/session/session_coordinator.dart';

apps/desktop/test/shell_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 2 (Status + Notifier): toasts and the status
+// pill; in step 3 (Your server): the solo strip and Invite friends.
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -79,6 +81,8 @@ void main() {
         autoUpdateCheck: false,
         windowControls: false,
         videoBuilder: (context, controls) => const FakeVideo(),
+        // A real probe (network, yt-dlp) never answers on the test clock.
+        linkProbe: (url) async => LinkProbe.file(Uri.parse(url), 1000),
       ),
     ));
     await tester.pumpAndSettle();
@@ -192,18 +196,6 @@ void main() {
       expect(tester.takeException(), isNull);
     });
 
-    testWidgets('tabs: the underline moves to the selected one', (tester) async {
-      await pumpShell(tester, const Size(1280, 800));
-      double underline(String tab) => tester
-          .getSize(find.descendant(of: find.byKey(ValueKey('tab-$tab')), matching: find.byType(AnimatedContainer)))
-          .width;
-      expect(underline('library'), 22);
-      expect(underline('settings'), 0);
-      await tester.tap(find.byKey(const ValueKey('tab-settings')));
-      await tester.pumpAndSettle();
-      expect(underline('library'), 0);
-      expect(underline('settings'), 22);
-    });
   });
 
   group('popovers', () {
@@ -418,16 +410,4 @@ void main() {
     await tester.pumpAndSettle();
     expect(find.text('Shaders off'), findsNothing);
   });
-
-  testWidgets('status avatar fills its box at any size', (tester) async {
-    await tester.pumpWidget(const MaterialApp(
-      home: Center(
-        child: StatusAvatar(info: AvatarInfo(name: 'Zed', color: Colors.teal, ready: true), size: 88),
-      ),
-    ));
-    final circle = tester.getSize(find.byType(CircleAvatar));
-    // Ring and gap (2 x 4 px each side at this size) inside the 88 px box.
-    expect(circle.width, 88 - 4 * 4);
-    expect(find.text('Z'), findsOneWidget);
-  });
 }

apps/desktop/test/video_reload_e2e_test.dart

@@ -1,3 +1,5 @@
+// restructure: rewrite in step 6 (Media pipeline + player host): the
+// fresh player per video.
 import 'dart:async';
 
 import 'package:flutter_test/flutter_test.dart';