Desktop: video freeze recovery, session fixes, Home redesign

- Player + VideoController per session; Reload video (Ctrl+R) and a
  frozen-picture watchdog that reloads automatically.
- Shortcuts no longer fire while typing; empty swap disabled;
  hwdec setting/env actually applied.
- Idle unready measured from real inactivity; cancellable reconnects
  and setup; ready restored from server state; kicked/failed host
  stops its server; graceful leave on window close; no URLs with
  keys in display names.
- Welcome + connect screens replaced by one Home screen with Join and
  Host cards, recent servers, Settings, Integrations and About.

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

apps/desktop/lib/src/widgets/shown_frame_probe.dart

@@ -0,0 +1,66 @@
+import 'dart:ui' as ui;
+
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+
+import '../playback/frame_watchdog.dart';
+
+/// Fingerprints what the compositor really shows of the video. Place
+/// [anchor] in the video controls (built in the window and again in the
+/// fullscreen route); [sample] captures the route around the newest
+/// mounted anchor at ~200 px wide — the texture included — and hashes its
+/// centre. This is the only per-presented-frame signal: mpv's own
+/// counters keep ticking when the Flutter texture is stuck.
+class ShownFrameProbe {
+  final _anchors = <_AnchorState>[];
+
+  Widget anchor() => _Anchor(probe: this);
+
+  Future<int?> sample() async {
+    for (final a in _anchors.reversed) {
+      if (!a.mounted) continue;
+      final boundary = a.context.findAncestorRenderObjectOfType<RenderRepaintBoundary>();
+      if (boundary == null || !boundary.attached || !boundary.hasSize) return null;
+      final width = boundary.size.width;
+      if (width <= 0) return null;
+      ui.Image? image;
+      try {
+        image = await boundary.toImage(pixelRatio: (200 / width).clamp(0.02, 1.0));
+        final data = await image.toByteData(format: ui.ImageByteFormat.rawRgba);
+        if (data == null) return null;
+        return hashCenterPixels(data, image.width, image.height);
+      } catch (_) {
+        // Route not painted (covered) or mid-teardown: no reading.
+        return null;
+      } finally {
+        image?.dispose();
+      }
+    }
+    return null;
+  }
+}
+
+class _Anchor extends StatefulWidget {
+  final ShownFrameProbe probe;
+  const _Anchor({required this.probe});
+
+  @override
+  State<_Anchor> createState() => _AnchorState();
+}
+
+class _AnchorState extends State<_Anchor> {
+  @override
+  void initState() {
+    super.initState();
+    widget.probe._anchors.add(this);
+  }
+
+  @override
+  void dispose() {
+    widget.probe._anchors.remove(this);
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) => const SizedBox.shrink();
+}

apps/desktop/lib/src/widgets/text_focus.dart

@@ -0,0 +1,9 @@
+import 'package:flutter/widgets.dart';
+
+/// True while keyboard focus sits in a text field. The focused node's
+/// context belongs to the `Focus` that `EditableText` builds, so look for
+/// an `EditableText` above it (walking FocusNode parents never meets one).
+bool textInputFocused([FocusNode? node]) {
+  final n = node ?? FocusManager.instance.primaryFocus;
+  return n?.context?.findAncestorWidgetOfExactType<EditableText>() != null;
+}