refactor(command-palette): extract groups into declarative registry

src/components/command-palette/registry/groups/files.tsx

@@ -0,0 +1,27 @@
+import { FileText } from 'lucide-react';
+
+import { useFilesSource } from '../../sources/useFilesSource';
+import type { GroupConfig } from '../types';
+
+export const filesGroup: GroupConfig = {
+  id: 'files',
+  heading: 'Files',
+  modes: ['mixed', 'files'],
+  prefix: { char: '/', mode: 'files' },
+  requiresProject: true,
+  useItems: (ctx) => {
+    const { items: files } = useFilesSource(ctx.projectId, ctx.enabled);
+    return files.map((f) => ({
+      key: `file-${f.path}`,
+      value: f.path,
+      onSelect: () => ctx.run(() => ctx.openFile(f.path)),
+      node: (
+        <>
+          <FileText className="h-4 w-4 shrink-0 text-muted-foreground" aria-hidden />
+          <span className="flex-1 truncate">{f.name}</span>
+          <span className="truncate text-xs text-muted-foreground">{f.path}</span>
+        </>
+      ),
+    }));
+  },
+};