Release @pi/ui 0.0.6: pi-file-upload keeps its own look

Its drop zone is a <button>, so the library's global button rules
squashed it to the button height and dropped its dashed border. It is
left out of them, like Material's own buttons.

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

libs/ui/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@pi/ui",
-  "version": "0.0.5",
+  "version": "0.0.6",
   "description": "Librería de componentes Angular standalone (botones, campos con Signal Forms, cards, charts, drawer/hub/modal, theming vía tokens CSS...).",
   "license": "MIT",
   "generators": "./generators.json",