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/layout/Sidebar.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { ui } from '$lib/stores/ui.svelte.js';
 	import { page } from '$app/stores';
+	import DynamicIcon from '$lib/components/ui/DynamicIcon.svelte';
 
 	interface BoardLink {
 		id: string;
@@ -150,7 +151,7 @@
 						onclick={() => ui.closeMobileSidebar()}
 					>
 						{#if board.icon}
-							<span class="shrink-0 text-base">{board.icon}</span>
+							<span class="shrink-0"><DynamicIcon name={board.icon} size={18} /></span>
 						{:else}
 							<span
 								class="flex h-5 w-5 shrink-0 items-center justify-center rounded bg-sidebar-accent text-[10px] font-medium text-sidebar-foreground"