refactor: change show mask flow - checkbox in params

web/src/lib/components/tool/ParamsCard.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+	import CheckboxField from '../ui/CheckboxField.svelte';
 	import ParamForm from '../ParamForm.svelte';
 	import type { ParamDef } from '$lib/registry';
 
@@ -7,16 +8,28 @@
 		values: Record<string, any>;
 		pipetteTargetId?: string | null;
 		onPipetteToggle?: (id: string) => void;
+		hasMask?: boolean;
+		showMask?: boolean;
 	}
 
-	let { params, values = $bindable(), pipetteTargetId = null, onPipetteToggle }: Props = $props();
+	let {
+		params,
+		values = $bindable(),
+		pipetteTargetId = null,
+		onPipetteToggle,
+		hasMask = false,
+		showMask = $bindable(false)
+	}: Props = $props();
 </script>
 
 <div class="panel root">
 	<h2 class="heading-section">Параметры</h2>
+	{#if hasMask}
+		<CheckboxField id="show-mask" label="Показать маску" bind:checked={showMask} />
+	{/if}
 	{#if params.length > 0}
 		<ParamForm {params} bind:values {pipetteTargetId} {onPipetteToggle} />
-	{:else}
+	{:else if !hasMask}
 		<p class="hint text-caption text-muted">
 			У этого инструмента нет параметров — результат уже готов.
 		</p>

web/src/lib/components/tool/ResultCard.svelte

@@ -1,5 +1,4 @@
 <script lang="ts">
-	import CheckboxField from '../ui/CheckboxField.svelte';
 	import Button from '../ui/Button.svelte';
 	import DownloadButton from '../DownloadButton.svelte';
 	import EmptyState from '../ui/EmptyState.svelte';
@@ -17,8 +16,7 @@
 		sourceLoaded: boolean;
 		status: Status;
 		result: PixelImage | null;
-		previewResult: PixelImage | null;
-		showMask: boolean;
+		displayImage: PixelImage | null;
 		info: ImageInfo | null;
 		isInfo: boolean;
 		params: Record<string, unknown>;
@@ -33,8 +31,7 @@
 		sourceLoaded,
 		status,
 		result,
-		previewResult,
-		showMask = $bindable(false),
+		displayImage,
 		info,
 		isInfo,
 		params,
@@ -43,9 +40,6 @@
 		hasChain = false,
 		onDownloadError
 	}: Props = $props();
-
-	const hasPreview = $derived(typeof tool.preview === 'function');
-	const shown = $derived(showMask && previewResult ? previewResult : result);
 </script>
 
 <div class="container">
@@ -77,11 +71,8 @@
 			{/if}
 		</div>
 	{:else}
-		{#if hasPreview}
-			<CheckboxField id="show-mask" label="Показать маску" bind:checked={showMask} />
-		{/if}
 		<div class="media">
-			<Preview image={shown} />
+			<Preview image={displayImage} />
 			{#if status === 'processing'}
 				<span class="recalc" aria-live="polite">Пересчёт…</span>
 			{/if}