Replace template text input with searchable combobox, lock specs for snapshots

Template field is now a filterable dropdown that fetches available
templates on dialog open. Selecting a snapshot auto-fills and disables
vCPU/memory inputs since they must match the original capsule config.

frontend/src/lib/components/CreateCapsuleDialog.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
-	import { createCapsule, type Capsule, type CreateCapsuleParams } from '$lib/api/capsules';
+	import { onMount } from 'svelte';
+	import { createCapsule, listSnapshots, type Capsule, type CreateCapsuleParams, type Snapshot } from '$lib/api/capsules';
 
 	type Props = {
 		open: boolean;
@@ -12,12 +13,109 @@
 	let creating = $state(false);
 	let createError = $state<string | null>(null);
 
+	// Template combobox state
+	let templates = $state<Snapshot[]>([]);
+	let templatesLoading = $state(false);
+	let templateQuery = $state('');
+	let comboOpen = $state(false);
+	let highlightIdx = $state(-1);
+	let inputEl = $state<HTMLInputElement | undefined>(undefined);
+	let listEl = $state<HTMLUListElement | undefined>(undefined);
+
+	// Snapshots have fixed CPU/RAM from the snapshot state — users cannot override.
+	let selectedIsSnapshot = $derived(
+		templates.find((t) => t.name === createForm.template)?.type === 'snapshot'
+	);
+
+	let filtered = $derived.by(() => {
+		const q = templateQuery.toLowerCase();
+		if (!q) return templates;
+		return templates.filter((t) => t.name.toLowerCase().includes(q));
+	});
+
+	// Fetch templates when dialog opens
+	$effect(() => {
+		if (open && templates.length === 0 && !templatesLoading) {
+			templatesLoading = true;
+			listSnapshots().then((result) => {
+				if (result.ok) templates = result.data;
+				templatesLoading = false;
+			});
+		}
+		if (open) {
+			templateQuery = createForm.template ?? '';
+		}
+	});
+
+	function selectTemplate(t: Snapshot) {
+		createForm.template = t.name;
+		templateQuery = t.name;
+		// Pre-fill specs from the template if available
+		if (t.vcpus) createForm.vcpus = t.vcpus;
+		if (t.memory_mb) createForm.memory_mb = t.memory_mb;
+		comboOpen = false;
+		highlightIdx = -1;
+	}
+
+	function handleInputKeydown(e: KeyboardEvent) {
+		if (!comboOpen && (e.key === 'ArrowDown' || e.key === 'ArrowUp')) {
+			comboOpen = true;
+			highlightIdx = 0;
+			e.preventDefault();
+			return;
+		}
+		if (!comboOpen) return;
+
+		if (e.key === 'ArrowDown') {
+			e.preventDefault();
+			highlightIdx = Math.min(highlightIdx + 1, filtered.length - 1);
+			scrollToHighlighted();
+		} else if (e.key === 'ArrowUp') {
+			e.preventDefault();
+			highlightIdx = Math.max(highlightIdx - 1, 0);
+			scrollToHighlighted();
+		} else if (e.key === 'Enter' && highlightIdx >= 0 && highlightIdx < filtered.length) {
+			e.preventDefault();
+			selectTemplate(filtered[highlightIdx]);
+		} else if (e.key === 'Escape') {
+			comboOpen = false;
+			highlightIdx = -1;
+		}
+	}
+
+	function scrollToHighlighted() {
+		if (!listEl) return;
+		const item = listEl.children[highlightIdx] as HTMLElement | undefined;
+		item?.scrollIntoView({ block: 'nearest' });
+	}
+
+	function handleInputFocus() {
+		comboOpen = true;
+		highlightIdx = -1;
+	}
+
+	function handleInputBlur() {
+		// Delay to allow click on dropdown item to fire first
+		setTimeout(() => {
+			comboOpen = false;
+			// If the typed query matches an existing template, apply it
+			const match = templates.find((t) => t.name === templateQuery);
+			if (match) {
+				createForm.template = match.name;
+			} else {
+				// Allow free-form entry (user might know a template name not in the list)
+				createForm.template = templateQuery;
+			}
+		}, 150);
+	}
+
 	async function handleCreate() {
 		creating = true;
 		createError = null;
 		const result = await createCapsule(createForm);
 		if (result.ok) {
 			createForm = { template: 'minimal', vcpus: 1, memory_mb: 512, timeout_sec: 0 };
+			templateQuery = 'minimal';
 			oncreated?.(result.data);
 			onclose();
 		} else {
@@ -47,16 +145,98 @@
 			{/if}
 
 			<div class="mt-5 space-y-4">
-				<div>
+				<!-- Template combobox -->
+				<div class="relative">
 					<label class="mb-1.5 block text-label font-semibold uppercase tracking-[0.05em] text-[var(--color-text-tertiary)]" for="create-template">Template</label>
+					<div class="relative">
 						<input
+							bind:this={inputEl}
 							id="create-template"
 							type="text"
-						bind:value={createForm.template}
+							role="combobox"
-						class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] px-3 py-2 font-mono text-ui text-[var(--color-text-bright)] outline-none placeholder:text-[var(--color-text-muted)] transition-colors duration-150 focus:border-[var(--color-accent)]"
+							aria-expanded={comboOpen}
-						placeholder="minimal"
+							aria-autocomplete="list"
+							aria-controls="template-listbox"
+							autocomplete="off"
+							bind:value={templateQuery}
+							onfocus={handleInputFocus}
+							onblur={handleInputBlur}
+							onkeydown={handleInputKeydown}
+							disabled={creating}
+							class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] py-2 pl-3 pr-8 font-mono text-ui text-[var(--color-text-bright)] outline-none placeholder:text-[var(--color-text-muted)] transition-colors duration-150 focus:border-[var(--color-accent)] disabled:opacity-60"
+							placeholder="Search templates..."
 						/>
-					<p class="mt-1.5 text-meta text-[var(--color-text-muted)]">Name of a snapshot or base image to boot from.</p>
+						<!-- Chevron -->
+						<svg
+							class="pointer-events-none absolute right-2.5 top-1/2 -translate-y-1/2 text-[var(--color-text-muted)] transition-transform duration-150 {comboOpen ? 'rotate-180' : ''}"
+							width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"
+						>
+							<polyline points="6 9 12 15 18 9" />
+						</svg>
+					</div>
+
+					<!-- Dropdown -->
+					{#if comboOpen}
+						<ul
+							bind:this={listEl}
+							id="template-listbox"
+							role="listbox"
+							class="absolute z-10 mt-1 max-h-[200px] w-full overflow-y-auto rounded-[var(--radius-input)] border border-[var(--color-border-mid)] bg-[var(--color-bg-3)] py-1 shadow-lg"
+							style="animation: fadeUp 0.12s ease both"
+						>
+							{#if templatesLoading}
+								<li class="flex items-center gap-2 px-3 py-2.5 text-meta text-[var(--color-text-muted)]">
+									<svg class="animate-spin" width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M21 12a9 9 0 1 1-6.219-8.56" /></svg>
+									Loading templates...
+								</li>
+							{:else if filtered.length === 0}
+								<li class="px-3 py-2.5 text-meta text-[var(--color-text-muted)]">
+									{templateQuery ? 'No matching templates' : 'No templates available'}
+								</li>
+							{:else}
+								{#each filtered as t, i (t.name)}
+									<!-- svelte-ignore a11y_click_events_have_key_events -->
+									<li
+										role="option"
+										aria-selected={i === highlightIdx}
+										class="flex cursor-pointer items-center gap-2.5 px-3 py-2 transition-colors duration-75
+											{i === highlightIdx
+												? 'bg-[var(--color-bg-5)] text-[var(--color-text-bright)]'
+												: 'text-[var(--color-text-primary)] hover:bg-[var(--color-bg-4)]'}
+											{createForm.template === t.name ? 'font-medium' : ''}"
+										onmousedown={(e) => { e.preventDefault(); selectTemplate(t); }}
+										onmouseenter={() => { highlightIdx = i; }}
+									>
+										<!-- Type badge -->
+										{#if t.type === 'snapshot'}
+											<span class="inline-flex shrink-0 items-center rounded-full border border-[var(--color-accent)]/25 bg-[var(--color-accent)]/8 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-[0.04em] text-[var(--color-accent-bright)]">
+												snap
+											</span>
+										{:else}
+											<span class="inline-flex shrink-0 items-center rounded-full border border-[var(--color-blue)]/25 bg-[var(--color-blue)]/8 px-1.5 py-0.5 text-[10px] font-semibold uppercase tracking-[0.04em] text-[var(--color-blue)]">
+												base
+											</span>
+										{/if}
+										<span class="truncate font-mono text-meta">{t.name}</span>
+										<!-- Specs hint -->
+										{#if t.vcpus && t.memory_mb}
+											<span class="ml-auto shrink-0 text-[10px] text-[var(--color-text-muted)]">
+												{t.vcpus}v · {t.memory_mb}MB
+											</span>
+										{/if}
+										<!-- Selected check -->
+										{#if createForm.template === t.name}
+											<svg class="ml-auto shrink-0 text-[var(--color-accent)]" width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
+												<polyline points="20 6 9 17 4 12" />
+											</svg>
+										{/if}
+									</li>
+								{/each}
+							{/if}
+						</ul>
+					{/if}
+
+					<p class="mt-1.5 text-meta text-[var(--color-text-muted)]">Snapshot or base image to boot from.</p>
 				</div>
 
 				<div class="grid grid-cols-2 gap-3">
@@ -68,7 +248,8 @@
 							min="1"
 							max="8"
 							bind:value={createForm.vcpus}
-							class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] px-3 py-2 font-mono text-ui text-[var(--color-text-bright)] outline-none transition-colors duration-150 focus:border-[var(--color-accent)]"
+							disabled={creating || selectedIsSnapshot}
+							class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] px-3 py-2 font-mono text-ui text-[var(--color-text-bright)] outline-none transition-colors duration-150 focus:border-[var(--color-accent)] disabled:opacity-60"
 						/>
 					</div>
 					<div>
@@ -80,7 +261,8 @@
 							max="8192"
 							step="128"
 							bind:value={createForm.memory_mb}
-							class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] px-3 py-2 font-mono text-ui text-[var(--color-text-bright)] outline-none transition-colors duration-150 focus:border-[var(--color-accent)]"
+							disabled={creating || selectedIsSnapshot}
+							class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] px-3 py-2 font-mono text-ui text-[var(--color-text-bright)] outline-none transition-colors duration-150 focus:border-[var(--color-accent)] disabled:opacity-60"
 						/>
 					</div>
 				</div>
@@ -92,7 +274,8 @@
 						type="number"
 						min="0"
 						bind:value={createForm.timeout_sec}
-						class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] px-3 py-2 font-mono text-ui text-[var(--color-text-bright)] outline-none transition-colors duration-150 focus:border-[var(--color-accent)]"
+						disabled={creating}
+						class="w-full rounded-[var(--radius-input)] border border-[var(--color-border)] bg-[var(--color-bg-4)] px-3 py-2 font-mono text-ui text-[var(--color-text-bright)] outline-none transition-colors duration-150 focus:border-[var(--color-accent)] disabled:opacity-60"
 						placeholder="0"
 					/>
 					<p class="mt-1.5 text-meta text-[var(--color-text-muted)]">Seconds of inactivity before the capsule pauses. Set to 0 to keep it running indefinitely.</p>