feat: add step picker\list\editor

web/src/lib/components/workspace/StepEditor.svelte

@@ -0,0 +1,41 @@
+<script lang="ts">
+	import ParamForm from '../ParamForm.svelte';
+	import type { PipelineStep } from '$lib/tools/pipeline';
+	import { getTool } from '$lib/registry';
+
+	interface Props {
+		step: PipelineStep;
+	}
+
+	let { step }: Props = $props();
+
+	const tool = $derived(getTool(step.toolId));
+</script>
+
+{#if tool}
+	<div class="editor panel">
+		<h3 class="heading-section">{tool.title}</h3>
+		<p class="description text-caption text-muted">{tool.description}</p>
+		{#if tool.params.length > 0}
+			<ParamForm params={tool.params} bind:values={step.values} />
+		{:else}
+			<p class="hint text-caption text-muted">У этого шага нет параметров.</p>
+		{/if}
+	</div>
+{/if}
+
+<style>
+	.editor {
+		padding: var(--space-3);
+	}
+
+	h3 {
+		margin-bottom: var(--space-1);
+		font-size: var(--text-m);
+	}
+
+	.description,
+	.hint {
+		margin: 0 0 var(--space-2);
+	}
+</style>

web/src/lib/components/workspace/StepList.svelte

@@ -0,0 +1,128 @@
+<script lang="ts">
+	import type { PipelineStep } from '$lib/tools/pipeline';
+	import { getTool } from '$lib/registry';
+
+	interface Props {
+		steps: PipelineStep[];
+		selectedIndex: number;
+		onSelect: (index: number) => void;
+		onMoveUp: (index: number) => void;
+		onMoveDown: (index: number) => void;
+		onRemove: (index: number) => void;
+	}
+
+	let { steps, selectedIndex, onSelect, onMoveUp, onMoveDown, onRemove }: Props = $props();
+
+	function toolTitle(step: PipelineStep): string {
+		return getTool(step.toolId)?.title ?? step.toolId;
+	}
+</script>
+
+{#if steps.length === 0}
+	<p class="empty text-caption text-muted">Цепочка пуста — добавьте первый инструмент.</p>
+{:else}
+	<ol>
+		{#each steps as step, index (step.id)}
+			<li>
+				<button type="button" class="label" class:selected={index === selectedIndex} onclick={() => onSelect(index)}>
+					<span class="num">{index + 1}</span>
+					{toolTitle(step)}
+				</button>
+				<span class="controls">
+					<button type="button" aria-label="Выше" disabled={index === 0} onclick={() => onMoveUp(index)}>↑</button>
+					<button
+						type="button"
+						aria-label="Ниже"
+						disabled={index === steps.length - 1}
+						onclick={() => onMoveDown(index)}
+					>↓</button>
+					<button type="button" class="remove" aria-label="Удалить шаг" onclick={() => onRemove(index)}>✕</button>
+				</span>
+			</li>
+		{/each}
+	</ol>
+{/if}
+
+<style>
+	ol {
+		list-style: none;
+		margin: 0;
+		padding: 0;
+		display: flex;
+		flex-direction: column;
+		gap: var(--space-1);
+	}
+
+	li {
+		display: flex;
+		align-items: center;
+		gap: var(--space-1);
+	}
+
+	.label {
+		flex: 1;
+		min-width: 0;
+		text-align: left;
+		padding: var(--space-1) var(--space-2);
+		border: 1px solid transparent;
+		border-radius: var(--radius-s);
+		background: none;
+		color: var(--text);
+		cursor: pointer;
+		font-size: var(--text-m);
+		overflow: hidden;
+		text-overflow: ellipsis;
+		white-space: nowrap;
+	}
+
+	.label:hover,
+	.label.selected {
+		background: color-mix(in srgb, var(--accent) 8%, var(--surface));
+		border-color: var(--border);
+	}
+
+	.num {
+		display: inline-block;
+		min-width: 1.4ch;
+		margin-right: var(--space-1);
+		color: var(--text-muted);
+		font-family: var(--font-mono);
+		font-size: var(--text-xs);
+	}
+
+	.controls {
+		display: flex;
+		gap: 2px;
+	}
+
+	.controls button {
+		width: 1.6rem;
+		height: 1.6rem;
+		padding: 0;
+		border: 1px solid var(--border);
+		border-radius: var(--radius-s);
+		background: var(--surface);
+		color: var(--text-muted);
+		line-height: 1;
+		cursor: pointer;
+	}
+
+	.controls button:hover:not(:disabled) {
+		border-color: var(--accent);
+		color: var(--accent);
+	}
+
+	.controls .remove:hover:not(:disabled) {
+		border-color: var(--danger);
+		color: var(--danger);
+	}
+
+	.controls button:disabled {
+		opacity: 0.4;
+		cursor: not-allowed;
+	}
+
+	.empty {
+		margin: 0;
+	}
+</style>

web/src/lib/components/workspace/StepPicker.svelte

@@ -0,0 +1,50 @@
+<script lang="ts">
+	import Button from '../ui/Button.svelte';
+	import { CATEGORIES } from '$lib/categories';
+	import { TOOLS } from '$lib/registry';
+
+	interface Props {
+		onAdd: (toolId: string) => void;
+	}
+
+	let { onAdd }: Props = $props();
+
+	const steppable = TOOLS.filter(
+		(tool) => (tool.resultType ?? 'image') === 'image' && (!tool.sourceMode || tool.sourceMode === 'file')
+	);
+
+	let selected = $state(steppable[0]?.id ?? '');
+</script>
+
+<div class="picker">
+	<select bind:value={selected} aria-label="Инструмент для нового шага">
+		{#each CATEGORIES as category (category.id)}
+			{@const categoryTools = steppable.filter((tool) => tool.category === category.id)}
+			{#if categoryTools.length > 0}
+				<optgroup label={category.label}>
+					{#each categoryTools as tool (tool.id)}
+						<option value={tool.id}>{tool.title}</option>
+					{/each}
+				</optgroup>
+			{/if}
+		{/each}
+	</select>
+	<Button variant="secondary" onclick={() => onAdd(selected)}>Добавить шаг</Button>
+</div>
+
+<style>
+	.picker {
+		display: flex;
+		gap: var(--space-2);
+		align-items: center;
+	}
+
+	select {
+		flex: 1;
+		min-width: 0;
+		padding: var(--space-1) var(--space-2);
+		border: 1px solid var(--border);
+		border-radius: var(--radius-s);
+		background: var(--surface);
+	}
+</style>

web/src/routes/+layout.svelte

@@ -14,6 +14,7 @@
 	<header>
 		<a href="/" class="brand">easy-png-tools</a>
 		<nav aria-label="Категории инструментов">
+			<a class="nav-link workspace-link" href="/workspace">Рабочая область</a>
 			{#each CATEGORIES as category (category.id)}
 				<a class="nav-link" href="/#{category.id}">{category.label}</a>
 			{/each}
@@ -79,6 +80,11 @@
 		text-decoration: none;
 	}
 
+	.workspace-link {
+		font-weight: 600;
+		color: var(--accent);
+	}
+
 	main {
 		flex: 1;
 		width: 100%;

web/src/routes/workspace/+page.svelte

@@ -0,0 +1,281 @@
+<script lang="ts">
+	import { clonePixelImage, type PixelImage } from '$lib/core/types';
+	import { decodeFile, isSupportedImage, unsupportedImageMessage } from '$lib/core/io';
+	import { getTool, PNG_OUTPUT, sanitizeParams } from '$lib/registry';
+	import { createAutoRunner } from '$lib/tools/auto-run';
+	import { createStep, type PipelineStep } from '$lib/tools/pipeline';
+	import DownloadButton from '$lib/components/DownloadButton.svelte';
+	import EmptyState from '$lib/components/ui/EmptyState.svelte';
+	import Preview from '$lib/components/Preview.svelte';
+	import SourceCard from '$lib/components/tool/SourceCard.svelte';
+	import StepEditor from '$lib/components/workspace/StepEditor.svelte';
+	import StepList from '$lib/components/workspace/StepList.svelte';
+	import StepPicker from '$lib/components/workspace/StepPicker.svelte';
+
+	type Status = 'idle' | 'loaded' | 'processing' | 'error';
+
+	const runner = createAutoRunner();
+	let hasLastRun = false;
+	let lastRunSource: PixelImage | null = null;
+	let lastRunStepsJson = '';
+
+	let status = $state<Status>('idle');
+	let source = $state<PixelImage | null>(null);
+	let steps = $state<PipelineStep[]>([]);
+	let selectedId = $state<string | null>(null);
+	let previews = $state<(PixelImage | null)[]>([]);
+	let errorText = $state('');
+
+	let selectedIndex = $derived.by(() => {
+		if (selectedId !== null) {
+			const index = steps.findIndex((step) => step.id === selectedId);
+			if (index >= 0) return index;
+		}
+		return steps.length - 1;
+	});
+
+	let shownResult = $derived.by(() => {
+		if (!source) return null;
+		if (previews.length === 0) return steps.length === 0 ? source : null;
+		const idx = Math.min(Math.max(selectedIndex, 0), previews.length - 1);
+		return previews[idx];
+	});
+
+	function addStep(toolId: string) {
+		steps.push(createStep(toolId));
+		selectedId = steps[steps.length - 1].id;
+	}
+
+	function moveUp(index: number) {
+		if (index <= 0) return;
+		const [moved] = steps.splice(index, 1);
+		steps.splice(index - 1, 0, moved);
+	}
+
+	function moveDown(index: number) {
+		if (index >= steps.length - 1) return;
+		const [moved] = steps.splice(index, 1);
+		steps.splice(index + 1, 0, moved);
+	}
+
+	function removeStep(index: number) {
+		if (index < 0 || index >= steps.length) return;
+		const removed = steps[index];
+		steps.splice(index, 1);
+		if (selectedId === removed.id) selectedId = null;
+	}
+
+	async function runChain() {
+		if (!source) return;
+		const token = runner.next();
+		hasLastRun = true;
+		lastRunSource = source;
+		lastRunStepsJson = JSON.stringify(steps);
+		status = 'processing';
+		errorText = '';
+		try {
+			const collected: PixelImage[] = [];
+			let current: PixelImage = clonePixelImage(source);
+			for (let i = 0; i < steps.length; i++) {
+				const step = steps[i];
+				const tool = getTool(step.toolId);
+				if (!tool?.run) continue;
+				try {
+					current = await tool.run(current, sanitizeParams(tool, step.values));
+				} catch (e) {
+					const message = e instanceof Error ? e.message : String(e);
+					throw new Error(`Шаг ${i + 1} (${tool.title}): ${message}`);
+				}
+				if (!runner.isCurrent(token)) return;
+				collected.push(current);
+			}
+			previews = collected;
+			status = 'loaded';
+		} catch (e) {
+			if (!runner.isCurrent(token)) return;
+			errorText = e instanceof Error ? e.message : String(e);
+			status = 'loaded';
+		}
+	}
+
+	$effect(() => {
+		const stepsJson = JSON.stringify(steps);
+		if (hasLastRun && source === lastRunSource && stepsJson === lastRunStepsJson) return;
+		if (!source) return;
+		return runner.schedule(() => void runChain());
+	});
+
+	function showError(message: string) {
+		errorText = message;
+	}
+
+	function reset() {
+		source = null;
+		previews = [];
+		status = 'idle';
+		errorText = '';
+	}
+
+	async function handleFile(file: File) {
+		if (!isSupportedImage(file)) {
+			showError(unsupportedImageMessage(file));
+			return;
+		}
+		try {
+			source = await decodeFile(file);
+		} catch (e) {
+			showError(e instanceof Error ? e.message : String(e));
+		}
+	}
+
+	function handlePaste(event: ClipboardEvent) {
+		for (const item of event.clipboardData?.items ?? []) {
+			if (!item.type.startsWith('image/')) continue;
+			const file = item.getAsFile();
+			if (!file) break;
+			event.preventDefault();
+			if (!isSupportedImage(file)) {
+				showError(unsupportedImageMessage(file));
+				break;
+			}
+			void handleFile(file);
+			break;
+		}
+	}
+</script>
+
+<svelte:window onpaste={handlePaste} />
+
+<section>
+	<h1>Рабочая область</h1>
+	<p class="description text-muted">
+		Цепочка инструментов: результат каждого шага становится входом следующего.
+	</p>
+
+	{#if errorText}
+		<div class="error-banner" role="alert">{errorText}</div>
+	{/if}
+
+	<div class="stage panel">
+		<div class="cell">
+			<SourceCard {source} onFile={handleFile} onError={showError} onReset={reset} />
+		</div>
+
+		<div class="cell middle">
+			<h2 class="heading-section">Шаги</h2>
+			<StepPicker onAdd={addStep} />
+			<StepList
+				{steps}
+				selectedIndex={selectedIndex}
+				onSelect={(index) => (selectedId = steps[index]?.id ?? null)}
+				onMoveUp={moveUp}
+				onMoveDown={moveDown}
+				onRemove={removeStep}
+			/>
+			{#if selectedIndex >= 0 && steps[selectedIndex]}
+				<StepEditor step={steps[selectedIndex]} />
+			{/if}
+		</div>
+
+		<div class="cell">
+			<h2 class="heading-section">Итог</h2>
+			{#if !source}
+				<div class="media">
+					<EmptyState
+						title="Итог появится здесь"
+						hint="Загрузите изображение и соберите цепочку шагов"
+					/>
+				</div>
+			{:else if status === 'processing' && !shownResult}
+				<div class="media">
+					<EmptyState title="Обработка…" hint="Выполняется цепочка шагов" />
+				</div>
+			{:else}
+				<div class="media">
+					<Preview image={shownResult} />
+					{#if status === 'processing'}
+						<span class="recalc" aria-live="polite">Пересчёт…</span>
+					{/if}
+				</div>
+				<DownloadButton
+					image={shownResult}
+					format={PNG_OUTPUT}
+					baseName="workspace"
+					params={{}}
+					onError={(e) => showError(e instanceof Error ? e.message : String(e))}
+				/>
+			{/if}
+		</div>
+	</div>
+</section>
+
+<style>
+	h1 {
+		margin-bottom: var(--space-1);
+	}
+
+	.description {
+		max-width: 48rem;
+		margin-bottom: var(--space-4);
+	}
+
+	.error-banner {
+		margin-bottom: var(--space-3);
+	}
+
+	.stage {
+		display: grid;
+		grid-template-columns: minmax(0, 1fr) minmax(16rem, 22rem) minmax(0, 1fr);
+		gap: var(--space-4);
+		padding: var(--space-4);
+		align-items: start;
+	}
+
+	.cell {
+		min-width: 0;
+		display: flex;
+		flex-direction: column;
+		gap: var(--space-2);
+	}
+
+	.cell h2 {
+		margin-bottom: var(--space-1);
+	}
+
+	.middle {
+		position: sticky;
+		top: var(--space-4);
+	}
+
+	.media {
+		flex: 1;
+		display: flex;
+		flex-direction: column;
+		align-items: center;
+		justify-content: center;
+		min-height: 14rem;
+		position: relative;
+		width: 100%;
+	}
+
+	.recalc {
+		position: absolute;
+		top: var(--space-2);
+		right: var(--space-2);
+		padding: 2px var(--space-2);
+		border-radius: var(--radius-s);
+		background: color-mix(in srgb, var(--accent) 12%, var(--surface));
+		color: var(--accent);
+		font-size: var(--text-xs);
+	}
+
+	@media (max-width: 64rem) {
+		.stage {
+			grid-template-columns: 1fr;
+		}
+
+		.middle {
+			position: static;
+		}
+	}
+</style>