style: replace all inline SVGs with Lucide icons

Swap every inline SVG across Header, SearchBar, NoteCard, NoteEditor,
Checklist, and ImageUpload for Lucide components. Use Palette for the
color picker icon instead of the paintbrush. Zero inline SVGs remain.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/components/SearchBar.svelte

@@ -1,6 +1,8 @@
 <script lang="ts">
 	import { notes, loadNotes, currentFilter } from '$lib/stores/notes.js';
 	import type { Note } from '$lib/types/index.js';
+	import Search from 'lucide-svelte/icons/search';
+	import X from 'lucide-svelte/icons/x';
 
 	let query = $state('');
 	let originalNotes: Note[] = [];
@@ -38,9 +40,7 @@
 
 <div class="relative max-w-2xl">
 	<div class="flex items-center rounded-sm border border-[var(--border-subtle)] bg-[var(--bg-base)] px-4 py-2 focus-within:border-[var(--primary)]">
-		<svg class="mr-3 h-5 w-5 text-[var(--text-muted)]" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-			<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z" />
-		</svg>
+		<Search class="mr-3 h-5 w-5 text-[var(--text-muted)]" />
 		<input
 			type="text"
 			placeholder="Search crumbs..."
@@ -51,9 +51,7 @@
 		/>
 		{#if query}
 			<button onclick={clearSearch} class="ml-2 text-[var(--text-muted)] hover:text-[var(--text)]" aria-label="Clear search">
-				<svg class="h-5 w-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-					<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12" />
-				</svg>
+				<X class="h-5 w-5" />
 			</button>
 		{/if}
 	</div>