fix: resolve runtime errors and missing routes

- Fix $effect orphan error: move $effect calls from store constructors
  to initEffects() methods called from component context
- Fix icon rendering: create DynamicIcon component to render Lucide icons
  from name strings instead of displaying raw text
- Add /boards/new route for board creation
- Fix seed emails (admin@launcher.local / user@launcher.local) to pass
  Zod email validation

src/lib/components/board/BoardCard.svelte

@@ -1,4 +1,6 @@
 <script lang="ts">
+	import DynamicIcon from '$lib/components/ui/DynamicIcon.svelte';
+
 	interface BoardSummary {
 		id: string;
 		name: string;
@@ -24,7 +26,7 @@
 >
 	<div class="flex items-start gap-3">
 		{#if board.icon}
-			<span class="text-xl">{board.icon}</span>
+			<DynamicIcon name={board.icon} size={22} />
 		{:else}
 			<span class="flex h-8 w-8 items-center justify-center rounded-md bg-muted text-sm text-muted-foreground">
 				B