fix(electrobun): fix PathBrowser process.env.HOME, add dual browse buttons

- PathBrowser: resolveHome() via files.homeDir RPC (was process.env.HOME)
- ProjectWizard: two browse buttons — 📂 native dialog + 🔍 in-app browser
- In-app browser uses display toggle (rule 55), dirs-only filter
- Native dialog: Electrobun Utils.openFileDialog (GTK chooser)
- In-app browser: themed, dirs sorted first, proper breadcrumbs

ui-electrobun/src/mainview/PathBrowser.svelte

@@ -9,7 +9,7 @@
 
   let { onSelect, onClose }: Props = $props();
 
-  const HOME = '/home/' + (typeof window !== 'undefined' ? '' : '');
+  let HOME = $state('/home');
   const SHORTCUTS = [
     { label: 'Home', path: '~' },
     { label: 'Desktop', path: '~/Desktop' },
@@ -40,11 +40,22 @@
     entries.filter(e => e.type === 'dir' && (filter === '' || e.name.toLowerCase().includes(filter.toLowerCase())))
   );
 
+  // Load home dir from backend on first use
+  async function resolveHome(): Promise<string> {
+    if (HOME !== '/home') return HOME;
+    try {
+      const r = await appRpc.request['files.homeDir']({});
+      if (r?.path) HOME = r.path;
+    } catch {}
+    return HOME;
+  }
+
   async function loadDir(dirPath: string) {
     loading = true;
     error = '';
     try {
-      const expandedPath = dirPath.replace(/^~/, process.env.HOME ?? '/home');
+      const home = await resolveHome();
+      const expandedPath = dirPath.replace(/^~/, home);
       const result = await appRpc.request['files.list']({ path: expandedPath });
       if (result?.error) {
         error = result.error;