feat(icons): extract shared workspace icon package

Create @workspace/icons as the single Hugeicons-backed Icon primitive and icon-data export surface, with size presets and inherited current color.

Migrate blocks and the web app to the shared package, remove duplicated direct Hugeicons dependencies and the blocks-local Icon component, and update the lockfile.

packages/icons/README.md

@@ -0,0 +1,22 @@
+# @workspace/icons
+
+Workspace icon primitives backed by Hugeicons.
+
+## Usage
+
+```tsx
+import { Icon, Search01Icon } from "@workspace/icons"
+
+export function SearchButton() {
+  return <Icon data={Search01Icon} size="lg" />
+}
+```
+
+`Icon` defaults to the `md` size and inherits the current text color. A
+Tailwind size class supplied through `className` overrides the size preset:
+
+```tsx
+<Icon data={Search01Icon} className="size-8 text-primary" />
+```
+
+Available presets are `xs`, `sm`, `md`, `lg`, and `xl`.