feat: add pipeline store

- Global pipeline configuration
- Built-in and user presets
- localStorage persistence
- Preset CRUD operations

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

src/lib/stores/pipeline.svelte.ts

@@ -0,0 +1,156 @@
+import {
+	type PipelineConfig,
+	type PipelinePreset,
+	DEFAULT_PIPELINE_CONFIG,
+	BUILT_IN_PRESETS,
+	clonePipelineConfig
+} from '$lib/types';
+
+const STORAGE_KEY = '2eink-pipeline-presets';
+
+function createPipelineStore() {
+	let globalConfig = $state<PipelineConfig>(clonePipelineConfig(DEFAULT_PIPELINE_CONFIG));
+	let selectedPresetId = $state<string | null>('default');
+	let userPresets = $state<PipelinePreset[]>([]);
+
+	const allPresets = $derived<PipelinePreset[]>([...BUILT_IN_PRESETS, ...userPresets]);
+
+	const selectedPreset = $derived<PipelinePreset | null>(
+		allPresets.find((p) => p.id === selectedPresetId) ?? null
+	);
+
+	const isModified = $derived<boolean>(() => {
+		if (!selectedPreset) return true;
+		return JSON.stringify(globalConfig) !== JSON.stringify(selectedPreset.config);
+	});
+
+	function loadPresets(): void {
+		if (typeof window === 'undefined') return;
+		try {
+			const stored = localStorage.getItem(STORAGE_KEY);
+			if (stored) {
+				userPresets = JSON.parse(stored);
+			}
+		} catch {
+			console.warn('Failed to load pipeline presets');
+		}
+	}
+
+	function savePresets(): void {
+		if (typeof window === 'undefined') return;
+		try {
+			localStorage.setItem(STORAGE_KEY, JSON.stringify(userPresets));
+		} catch {
+			console.warn('Failed to save pipeline presets');
+		}
+	}
+
+	function selectPreset(presetId: string): void {
+		const preset = allPresets.find((p) => p.id === presetId);
+		if (preset) {
+			globalConfig = clonePipelineConfig(preset.config);
+			selectedPresetId = presetId;
+		}
+	}
+
+	function updateConfig(updates: Partial<PipelineConfig>): void {
+		globalConfig = { ...globalConfig, ...updates };
+	}
+
+	function updateStep<K extends keyof PipelineConfig>(
+		step: K,
+		updates: Partial<PipelineConfig[K]>
+	): void {
+		globalConfig = {
+			...globalConfig,
+			[step]: { ...globalConfig[step], ...updates }
+		};
+	}
+
+	function saveAsPreset(name: string): PipelinePreset {
+		const id = `user-${Date.now()}`;
+		const preset: PipelinePreset = {
+			id,
+			name,
+			config: clonePipelineConfig(globalConfig),
+			isBuiltIn: false
+		};
+
+		userPresets = [...userPresets, preset];
+		selectedPresetId = id;
+		savePresets();
+
+		return preset;
+	}
+
+	function updatePreset(presetId: string): void {
+		const index = userPresets.findIndex((p) => p.id === presetId);
+		if (index === -1) return;
+
+		userPresets = userPresets.map((p) =>
+			p.id === presetId ? { ...p, config: clonePipelineConfig(globalConfig) } : p
+		);
+		savePresets();
+	}
+
+	function deletePreset(presetId: string): void {
+		const preset = userPresets.find((p) => p.id === presetId);
+		if (!preset || preset.isBuiltIn) return;
+
+		userPresets = userPresets.filter((p) => p.id !== presetId);
+		if (selectedPresetId === presetId) {
+			selectPreset('default');
+		}
+		savePresets();
+	}
+
+	function renamePreset(presetId: string, newName: string): void {
+		userPresets = userPresets.map((p) => (p.id === presetId ? { ...p, name: newName } : p));
+		savePresets();
+	}
+
+	function resetToDefault(): void {
+		selectPreset('default');
+	}
+
+	function getEffectiveConfig(imageOverride: PipelineConfig | null): PipelineConfig {
+		return imageOverride ?? globalConfig;
+	}
+
+	if (typeof window !== 'undefined') {
+		loadPresets();
+	}
+
+	return {
+		get globalConfig() {
+			return globalConfig;
+		},
+		get selectedPresetId() {
+			return selectedPresetId;
+		},
+		get selectedPreset() {
+			return selectedPreset;
+		},
+		get allPresets() {
+			return allPresets;
+		},
+		get userPresets() {
+			return userPresets;
+		},
+		get isModified() {
+			return isModified;
+		},
+		selectPreset,
+		updateConfig,
+		updateStep,
+		saveAsPreset,
+		updatePreset,
+		deletePreset,
+		renamePreset,
+		resetToDefault,
+		getEffectiveConfig,
+		loadPresets
+	};
+}
+
+export const pipelineStore = createPipelineStore();