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/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;
+}