Add live tag input with chips, autocomplete, and suggestions

Reusable TagInput component:
- Tags appear as blue chips instantly on comma/Enter press
- Remove tags by clicking X on the chip or Backspace when empty
- Autocomplete dropdown filters existing tags as you type
- All existing tags shown as clickable suggestions below
- Hidden input submits comma-separated value
- Applied to wiki new and edit pages

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/components/ui/TagInput.svelte

@@ -0,0 +1,99 @@
+<script lang="ts">
+	interface Props {
+		name?: string;
+		value?: string;
+		existingTags?: Array<{ id: string; name: string }>;
+	}
+
+	let { name = 'tags', value = '', existingTags = [] }: Props = $props();
+
+	let tags = $state<string[]>(value ? value.split(',').map(t => t.trim()).filter(Boolean) : []);
+	let input = $state('');
+
+	function addTag(tag: string) {
+		const t = tag.trim().toLowerCase();
+		if (t && !tags.includes(t)) {
+			tags = [...tags, t];
+		}
+		input = '';
+	}
+
+	function removeTag(tag: string) {
+		tags = tags.filter(t => t !== tag);
+	}
+
+	function handleKeydown(e: KeyboardEvent) {
+		if (e.key === ',' || e.key === 'Enter') {
+			e.preventDefault();
+			if (input.trim()) addTag(input);
+		} else if (e.key === 'Backspace' && !input && tags.length > 0) {
+			tags = tags.slice(0, -1);
+		}
+	}
+
+	function handleInput(e: Event) {
+		const val = (e.target as HTMLInputElement).value;
+		if (val.includes(',')) {
+			const parts = val.split(',');
+			for (const p of parts.slice(0, -1)) {
+				if (p.trim()) addTag(p);
+			}
+			input = parts[parts.length - 1];
+		} else {
+			input = val;
+		}
+	}
+
+	const suggestions = $derived(
+		input.length > 0
+			? existingTags.filter(t => t.name.includes(input.toLowerCase()) && !tags.includes(t.name))
+			: []
+	);
+
+	const hiddenValue = $derived(tags.join(', '));
+</script>
+
+<div>
+	<div class="flex flex-wrap items-center gap-1 rounded-md border border-gray-300 bg-white px-2 py-1.5 focus-within:border-blue-500 focus-within:ring-1 focus-within:ring-blue-500 dark:border-gray-600 dark:bg-gray-700">
+		{#each tags as tag}
+			<span class="flex items-center gap-1 rounded-full bg-blue-100 px-2 py-0.5 text-xs font-medium text-blue-700 dark:bg-blue-900/40 dark:text-blue-300">
+				{tag}
+				<button type="button" onclick={() => removeTag(tag)} aria-label="Remove {tag}" class="hover:text-blue-900 dark:hover:text-blue-100">
+					<svg class="h-3 w-3" 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>
+				</button>
+			</span>
+		{/each}
+		<input
+			type="text"
+			bind:value={input}
+			oninput={handleInput}
+			onkeydown={handleKeydown}
+			placeholder={tags.length === 0 ? 'Add tags...' : ''}
+			class="min-w-[80px] flex-1 border-0 bg-transparent px-1 py-0.5 text-sm outline-none dark:text-white dark:placeholder-gray-400"
+		/>
+	</div>
+
+	{#if suggestions.length > 0}
+		<div class="mt-1 rounded-md border border-gray-200 bg-white shadow-sm dark:border-gray-600 dark:bg-gray-700">
+			{#each suggestions.slice(0, 8) as tag}
+				<button type="button" onclick={() => addTag(tag.name)}
+					class="block w-full px-3 py-1.5 text-left text-sm text-gray-700 hover:bg-gray-100 dark:text-gray-300 dark:hover:bg-gray-600">
+					{tag.name}
+				</button>
+			{/each}
+		</div>
+	{/if}
+
+	{#if existingTags.length > 0 && input.length === 0}
+		<div class="mt-1 flex flex-wrap gap-1">
+			{#each existingTags.filter(t => !tags.includes(t.name)) as tag}
+				<button type="button" onclick={() => addTag(tag.name)}
+					class="rounded-full bg-gray-100 px-1.5 py-0.5 text-xs text-gray-600 hover:bg-gray-200 dark:bg-gray-700 dark:text-gray-400 dark:hover:bg-gray-600">
+					{tag.name}
+				</button>
+			{/each}
+		</div>
+	{/if}
+
+	<input type="hidden" {name} value={hiddenValue} />
+</div>

src/routes/(app)/wiki/[slug]/edit/+page.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { enhance } from '$app/forms';
 	import { marked } from 'marked';
+	import TagInput from '$lib/components/ui/TagInput.svelte';
 
 	let { data, form } = $props();
 
@@ -48,27 +49,8 @@
 		</div>
 
 		<div>
-			<label for="tags" class="mb-1 block text-sm font-medium text-gray-700 dark:text-gray-300">Tags</label>
+			<span class="mb-1 block text-sm font-medium text-gray-700 dark:text-gray-300">Tags</span>
-			<input type="text" id="tags" name="tags" value={data.currentTags}
+			<TagInput value={data.currentTags} existingTags={data.existingTags} />
-				placeholder="color-classic, bluescsi (comma-separated)"
-				class="w-full rounded-md border border-gray-300 px-3 py-2 text-sm focus:border-blue-500 focus:ring-1 focus:ring-blue-500 focus:outline-none dark:border-gray-600 dark:bg-gray-700 dark:text-white" />
-			{#if data.existingTags.length > 0}
-				<div class="mt-1 flex flex-wrap gap-1">
-					{#each data.existingTags as tag}
-						<button type="button"
-							onclick={() => {
-								const input = document.getElementById('tags') as HTMLInputElement;
-								const current = input.value.split(',').map(t => t.trim()).filter(Boolean);
-								if (!current.includes(tag.name)) {
-									input.value = [...current, tag.name].join(', ');
-								}
-							}}
-							class="rounded-full bg-gray-100 px-1.5 py-0.5 text-xs text-gray-600 hover:bg-gray-200 dark:bg-gray-700 dark:text-gray-400 dark:hover:bg-gray-600">
-							{tag.name}
-						</button>
-					{/each}
-				</div>
-			{/if}
 		</div>
 
 		<div>

src/routes/(app)/wiki/new/+page.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { enhance } from '$app/forms';
 	import { marked } from 'marked';
+	import TagInput from '$lib/components/ui/TagInput.svelte';
 
 	let { data, form } = $props();
 
@@ -47,27 +48,8 @@
 		</div>
 
 		<div>
-			<label for="tags" class="mb-1 block text-sm font-medium text-gray-700 dark:text-gray-300">Tags</label>
+			<span class="mb-1 block text-sm font-medium text-gray-700 dark:text-gray-300">Tags</span>
-			<input type="text" id="tags" name="tags"
+			<TagInput existingTags={data.existingTags} />
-				placeholder="color-classic, bluescsi, scsi (comma-separated)"
-				class="w-full rounded-md border border-gray-300 px-3 py-2 text-sm focus:border-blue-500 focus:ring-1 focus:ring-blue-500 focus:outline-none dark:border-gray-600 dark:bg-gray-700 dark:text-white dark:placeholder-gray-400" />
-			{#if data.existingTags.length > 0}
-				<div class="mt-1 flex flex-wrap gap-1">
-					{#each data.existingTags as tag}
-						<button type="button"
-							onclick={(e) => {
-								const input = document.getElementById('tags') as HTMLInputElement;
-								const current = input.value.split(',').map(t => t.trim()).filter(Boolean);
-								if (!current.includes(tag.name)) {
-									input.value = [...current, tag.name].join(', ');
-								}
-							}}
-							class="rounded-full bg-gray-100 px-1.5 py-0.5 text-xs text-gray-600 hover:bg-gray-200 dark:bg-gray-700 dark:text-gray-400 dark:hover:bg-gray-600">
-							{tag.name}
-						</button>
-					{/each}
-				</div>
-			{/if}
 		</div>
 
 		<!-- Markdown editor -->