♻️ refactor(shared-ui): remove lucide-svelte dependency

- Migrate ImmersiveModeToggle to use @manacore/shared-icons (CaretUp/CaretDown)
- Remove lucide-svelte from shared-ui package.json
- All shared-ui components now use Phosphor icons consistently

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/shared-ui/package.json

@@ -43,8 +43,7 @@
 		"d3-selection": "^3.0.0",
 		"d3-transition": "^3.0.0",
 		"d3-zoom": "^3.0.0",
-		"date-fns": "^4.1.0",
-		"lucide-svelte": "^0.468.0"
+		"date-fns": "^4.1.0"
 	},
 	"devDependencies": {
 		"@types/d3-force": "^3.0.10",