feat(app-form): icon picker, tag/category autocomplete, typography

- Replace AppIconPicker text input with visual IconPickerButton for
  lucide icons (grid with search)
- Add AutocompleteInput component for category field with existing
  category suggestions
- Add TagsInput component for tags field with tag pills, autocomplete
  from existing tags, and keyboard navigation
- Add GET /api/apps/suggestions endpoint returning all categories/tags
- Add getAllTags() to appService (merges Tag model + comma-separated)
- Install @tailwindcss/typography plugin to fix prose rendering
  (headings, lists, blockquotes now render in Note/Markdown widgets)
- Fix note widget validator test for new html format

package.json

@@ -24,6 +24,7 @@
 		"@sveltejs/adapter-node": "^5.2.0",
 		"@sveltejs/kit": "^2.16.0",
 		"@sveltejs/vite-plugin-svelte": "^5.0.0",
+		"@tailwindcss/typography": "^0.5.19",
 		"bcryptjs": "^2.4.3",
 		"bits-ui": "^1.3.0",
 		"clsx": "^2.1.0",