root-cause T-122 + restore 95% coverage; fix recents-row overflow

T-122: WelcomeView "hangs when recents are non-empty" was not a render/marquee
bug — SettingsStore.set does real file I/O, and awaiting settings.set +
loadRecents inside a testWidgets body runs it in fake-async, trapping the
completion so the await never returns. Fix: seed via tester.runAsync. Un-skip
the welcome recents test; add render/sticky/open-recent coverage.

Coverage: new test/app_test.dart covers the app shell (RootLayout, slots,
rails, spines, editor split, hat bar, intents, keymap, project switcher +
dialogs); welcome recents + events/types fill the rest. Total 92.04% -> 95.13%.

Also fixes a real bug found en route: the recent-project row (welcome +
switcher) overflowed instead of ellipsizing a long path (T-122).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/app.dart

@@ -583,7 +583,12 @@ class _RecentProjectRow extends StatelessWidget {
                   if (project.branch != null)
                     Row(
                       children: [
-                        ClideText(project.relativePath, muted: true, fontSize: 12, fontFamily: clideMonoFamily),
+                        // Elide a long path instead of overflowing the row
+                        // (matches the welcome recents row; T-160 discipline).
+                        Flexible(
+                          child: ClideText(project.relativePath,
+                              muted: true, fontSize: 12, fontFamily: clideMonoFamily, maxLines: 1, overflow: TextOverflow.ellipsis),
+                        ),
                         ClideText('  ·  ', muted: true, fontSize: 12),
                         ClideIcon(PhosphorIcons.gitBranch, size: 10, color: tokens.globalTextMuted),
                         const SizedBox(width: 3),
@@ -591,7 +596,7 @@ class _RecentProjectRow extends StatelessWidget {
                       ],
                     )
                   else
-                    ClideText(project.relativePath, muted: true, fontSize: 12, fontFamily: clideMonoFamily),
+                    ClideText(project.relativePath, muted: true, fontSize: 12, fontFamily: clideMonoFamily, maxLines: 1, overflow: TextOverflow.ellipsis),
                 ],
               ),
             ),