shared ToolCheck service, welcome status, logo doubled

ToolCheck kernel service checks ptyc/pql/tmux/git availability
once at boot, shared by status bar and welcome screen. Welcome
status line shows "application ok" in green or lists missing
tools in amber. Logo doubled to 144px. DialogHost moved inside
Expanded to fix blank workspace. Welcome maxWidth 850px, path
overflow fixed with Flexible.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/builtin/welcome/src/welcome_view.dart

@@ -57,8 +57,8 @@ class _Header extends StatelessWidget {
       crossAxisAlignment: CrossAxisAlignment.center,
       children: [
         SizedBox(
-          width: 72,
-          height: 72,
+          width: 144,
+          height: 144,
           child: ScalableImageWidget.fromSISource(
             si: ScalableImageSource.fromSvg(rootBundle, 'assets/logo/logo.svg'),
           ),
@@ -272,21 +272,21 @@ class _StatusLine extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final themeName = kernel.theme.currentName;
     return ListenableBuilder(
-      listenable: kernel.ipc,
+      listenable: kernel.toolCheck,
       builder: (ctx, _) {
-        final connected = kernel.ipc.isConnected;
-        final themeName = kernel.theme.currentName;
+        final tc = kernel.toolCheck;
         return Row(
           children: [
             ClideText('clide 2.0.0-dev', muted: true, fontSize: 12, fontFamily: clideMonoFamily),
             ClideText('  ·  ', muted: true, fontSize: 12),
-            ClideText(
-              connected ? 'daemon connected' : 'daemon disconnected',
-              fontSize: 12,
-              fontFamily: clideMonoFamily,
-              color: connected ? tokens.statusSuccess : tokens.statusError,
-            ),
+            if (!tc.checked)
+              ClideText('checking…', muted: true, fontSize: 12, fontFamily: clideMonoFamily)
+            else if (tc.allOk)
+              ClideText('application ok', fontSize: 12, fontFamily: clideMonoFamily, color: tokens.statusSuccess)
+            else
+              ClideText(tc.errors.join(' · '), fontSize: 12, fontFamily: clideMonoFamily, color: tokens.statusWarning),
             ClideText('  ·  ', muted: true, fontSize: 12),
             ClideText('theme: ', muted: true, fontSize: 12, fontFamily: clideMonoFamily),
             ClideText(themeName, fontSize: 12, fontFamily: clideMonoFamily, color: tokens.globalFocus),