diff --git a/docs/architecture-audit-2026-10.md b/docs/architecture-audit-2026-10.md
index 77a2752..63358c2 100644
--- a/docs/architecture-audit-2026-10.md
+++ b/docs/architecture-audit-2026-10.md
@@ -166,13 +166,19 @@ round-семантика `clampByte` и trunc-семантика `clampInt` со
 `$bindable`, пропс `ontogglealign` удалён; `SchemaToolView` передаёт
 `bind:aligned`.
 
-### L4. Непроверяемые `as`-касты схемы
+### L4. Непроверяемые `as`-касты схемы — СДЕЛАНО (2026-10)
 
-`SchemaToolView.svelte:97,211`
-(`tool.schema as ToolSchema<Record<string, unknown>>`) и паттерн `spec as XSpec`
-в 14+ field-компонентах (`CheckboxControl.svelte:13`, `ColorControl.svelte:14`,
-`GradientControl.svelte:16` и др.); двойной каст `as unknown as WorkerLike` в
-`executor/executor.ts:35`. Касты отключают проверку соответствия spec kind'у.
+- 14 field-контролов: `spec: FieldSpec` + `spec as XSpec` → точный тип спеки в
+  пропсах (`spec: ColorSpec` и т.д.); каст собран в одном месте — типизированный
+  хелпер `controlFor<S>()` в `SchemaFields.svelte` (ключ kind в `FIELDS`
+  гарантирует подтип спеки по `fieldSpecs`).
+- `SchemaToolView`/`toolSchemaOf`: касты
+  `as ToolSchema<Record<string, unknown>>` удалены — дефолт дженерика
+  `Tool<P = Record<string, unknown>>` уже даёт нужный тип; `undefined`
+  обрабатывается гардами (`{#if stepSchema}` в разметке, `dims && stepSchema` в
+  `setStepValue`).
+- `executor.ts` `as unknown as WorkerLike` оставлен намеренно: несовместимость
+  `onerror` (ErrorEvent vs Event) в типах lib.dom; добавлен комментарий-причина.
 
 ### L5. Хардкод slug-ов вне registry
 
diff --git a/web/src/lib/components/fields/schema/CheckboxControl.svelte b/web/src/lib/components/fields/schema/CheckboxControl.svelte
index 1e4f99a..b42ffa2 100644
--- a/web/src/lib/components/fields/schema/CheckboxControl.svelte
+++ b/web/src/lib/components/fields/schema/CheckboxControl.svelte
@@ -1,16 +1,16 @@
 <script lang="ts">
-	import type { CheckboxSpec, FieldSpec } from "$lib/registry-schema";
+	import type { CheckboxSpec } from "$lib/registry-schema";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: CheckboxSpec;
 		onchange?: (value: boolean) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as CheckboxSpec);
+	const sp = $derived(spec);
 	const current = $derived(
 		typeof value === "boolean" ? value : Boolean(sp.default),
 	);
diff --git a/web/src/lib/components/fields/schema/ColorControl.svelte b/web/src/lib/components/fields/schema/ColorControl.svelte
index 1e8c0ad..6e800f2 100644
--- a/web/src/lib/components/fields/schema/ColorControl.svelte
+++ b/web/src/lib/components/fields/schema/ColorControl.svelte
@@ -1,17 +1,17 @@
 <script lang="ts">
-	import type { ColorSpec, FieldSpec } from "$lib/registry-schema";
+	import type { ColorSpec } from "$lib/registry-schema";
 	import ColorSwatchInput from "./ColorSwatchInput.svelte";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: ColorSpec;
 		onchange?: (value: string) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as ColorSpec);
+	const sp = $derived(spec);
 	const current = $derived(typeof value === "string" ? value : sp.default);
 </script>
 
diff --git a/web/src/lib/components/fields/schema/ColorPairControl.svelte b/web/src/lib/components/fields/schema/ColorPairControl.svelte
index 43ae765..9ae9b8c 100644
--- a/web/src/lib/components/fields/schema/ColorPairControl.svelte
+++ b/web/src/lib/components/fields/schema/ColorPairControl.svelte
@@ -1,22 +1,18 @@
 <script lang="ts">
 	import { t } from "$lib/i18n/t";
-	import type {
-		ColorPair,
-		ColorPairSpec,
-		FieldSpec,
-	} from "$lib/registry-schema";
+	import type { ColorPair, ColorPairSpec } from "$lib/registry-schema";
 	import ColorSwatchInput from "./ColorSwatchInput.svelte";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: ColorPairSpec;
 		onchange?: (value: ColorPair) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as ColorPairSpec);
+	const sp = $derived(spec);
 	const current = $derived.by(() => {
 		const v = value as Partial<ColorPair> | undefined;
 		return {
diff --git a/web/src/lib/components/fields/schema/ColorsControl.svelte b/web/src/lib/components/fields/schema/ColorsControl.svelte
index d3ccdea..2584631 100644
--- a/web/src/lib/components/fields/schema/ColorsControl.svelte
+++ b/web/src/lib/components/fields/schema/ColorsControl.svelte
@@ -3,22 +3,18 @@
 	import Button from "$lib/components/ui/Button.svelte";
 	import IconButton from "$lib/components/ui/IconButton.svelte";
 	import { t } from "$lib/i18n/t";
-	import type {
-		ColorList,
-		ColorListSpec,
-		FieldSpec,
-	} from "$lib/registry-schema";
+	import type { ColorList, ColorListSpec } from "$lib/registry-schema";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: ColorListSpec;
 		onchange?: (value: ColorList) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as ColorListSpec);
+	const sp = $derived(spec);
 	const current = $derived.by((): ColorList => {
 		if (Array.isArray(value)) {
 			const valid = value.filter(
diff --git a/web/src/lib/components/fields/schema/DimensionField.svelte b/web/src/lib/components/fields/schema/DimensionField.svelte
index fc8b0ad..b8e074b 100644
--- a/web/src/lib/components/fields/schema/DimensionField.svelte
+++ b/web/src/lib/components/fields/schema/DimensionField.svelte
@@ -4,7 +4,6 @@
 		SIZE_PRESETS,
 		type Dimension,
 		type DimensionSpec,
-		type FieldSpec,
 	} from "$lib/registry-schema";
 	import ChipButton from "$lib/components/ui/ChipButton.svelte";
 	import Control from "./Control.svelte";
@@ -12,7 +11,7 @@
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: DimensionSpec;
 		/** Step input dimensions: axis cap for maxFromSource fields. */
 		sourceDims?: Dimension;
 		onchange?: (value: Dimension, axis?: "width" | "height" | "both") => void;
@@ -25,7 +24,7 @@
 		onchange,
 	}: Props = $props();
 
-	const sp = $derived(spec as DimensionSpec);
+	const sp = $derived(spec);
 	const maxW = $derived(
 		sp.maxFromSource && sourceDims ? sourceDims.width : sp.max,
 	);
diff --git a/web/src/lib/components/fields/schema/FontStyleControl.svelte b/web/src/lib/components/fields/schema/FontStyleControl.svelte
index 2fd4677..32783d4 100644
--- a/web/src/lib/components/fields/schema/FontStyleControl.svelte
+++ b/web/src/lib/components/fields/schema/FontStyleControl.svelte
@@ -1,23 +1,19 @@
 <script lang="ts">
 	import { t } from "$lib/i18n/t";
 	import type { TextFont } from "$lib/core/domText";
-	import type {
-		FieldSpec,
-		FontStyle,
-		FontStyleSpec,
-	} from "$lib/registry-schema";
+	import type { FontStyle, FontStyleSpec } from "$lib/registry-schema";
 	import ColorSwatchInput from "./ColorSwatchInput.svelte";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: FontStyleSpec;
 		onchange?: (value: FontStyle) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as FontStyleSpec);
+	const sp = $derived(spec);
 	const current = $derived.by(() => {
 		const v = value as Partial<FontStyle> | undefined;
 		return {
diff --git a/web/src/lib/components/fields/schema/GradientControl.svelte b/web/src/lib/components/fields/schema/GradientControl.svelte
index de97ec9..cd45b48 100644
--- a/web/src/lib/components/fields/schema/GradientControl.svelte
+++ b/web/src/lib/components/fields/schema/GradientControl.svelte
@@ -3,17 +3,17 @@
 	import ColorSwatchInput from "./ColorSwatchInput.svelte";
 	import Control from "./Control.svelte";
 	import { t } from "$lib/i18n/t";
-	import type { FieldSpec, Gradient, GradientSpec } from "$lib/registry-schema";
+	import type { Gradient, GradientSpec } from "$lib/registry-schema";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: GradientSpec;
 		onchange?: (value: Gradient) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as GradientSpec);
+	const sp = $derived(spec);
 	const current = $derived.by(() => {
 		const v = value as Partial<Gradient> | undefined;
 		return {
diff --git a/web/src/lib/components/fields/schema/OffsetControl.svelte b/web/src/lib/components/fields/schema/OffsetControl.svelte
index 2c513df..35d00f6 100644
--- a/web/src/lib/components/fields/schema/OffsetControl.svelte
+++ b/web/src/lib/components/fields/schema/OffsetControl.svelte
@@ -1,16 +1,16 @@
 <script lang="ts">
-	import type { FieldSpec, Offset, OffsetSpec } from "$lib/registry-schema";
+	import type { Offset, OffsetSpec } from "$lib/registry-schema";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: OffsetSpec;
 		onchange?: (value: Offset) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as OffsetSpec);
+	const sp = $derived(spec);
 	const current = $derived.by(() => {
 		const v = value as Partial<Offset> | undefined;
 		return {
diff --git a/web/src/lib/components/fields/schema/PlateControl.svelte b/web/src/lib/components/fields/schema/PlateControl.svelte
index e9c4134..27883dc 100644
--- a/web/src/lib/components/fields/schema/PlateControl.svelte
+++ b/web/src/lib/components/fields/schema/PlateControl.svelte
@@ -1,18 +1,18 @@
 <script lang="ts">
 	import { t } from "$lib/i18n/t";
-	import type { FieldSpec, Plate, PlateSpec } from "$lib/registry-schema";
+	import type { Plate, PlateSpec } from "$lib/registry-schema";
 	import ColorSwatchInput from "./ColorSwatchInput.svelte";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: PlateSpec;
 		onchange?: (value: Plate) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as PlateSpec);
+	const sp = $derived(spec);
 	const current = $derived.by(() => {
 		const v = value as Partial<Plate> | undefined;
 		return {
diff --git a/web/src/lib/components/fields/schema/PositionControl.svelte b/web/src/lib/components/fields/schema/PositionControl.svelte
index 41e39e8..400b286 100644
--- a/web/src/lib/components/fields/schema/PositionControl.svelte
+++ b/web/src/lib/components/fields/schema/PositionControl.svelte
@@ -1,21 +1,17 @@
 <script lang="ts">
 	import type { Position9 } from "$lib/core/textdraw";
-	import {
-		POSITION9_VALUES,
-		type FieldSpec,
-		type Position9Spec,
-	} from "$lib/registry-schema";
+	import { POSITION9_VALUES, type Position9Spec } from "$lib/registry-schema";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: Position9Spec;
 		onchange?: (value: Position9) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as Position9Spec);
+	const sp = $derived(spec);
 	const current = $derived(
 		typeof value === "string" &&
 			(POSITION9_VALUES as readonly string[]).includes(value)
diff --git a/web/src/lib/components/fields/schema/RangeControl.svelte b/web/src/lib/components/fields/schema/RangeControl.svelte
index f3dd094..8f13d46 100644
--- a/web/src/lib/components/fields/schema/RangeControl.svelte
+++ b/web/src/lib/components/fields/schema/RangeControl.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { FieldSpec, NumberSpec, SliderSpec } from "$lib/registry-schema";
+	import type { NumberSpec, SliderSpec } from "$lib/registry-schema";
 	import { t } from "$lib/i18n/t";
 	import { Minus, Plus, RotateCcw } from "@lucide/svelte";
 	import IconButton from "$lib/components/ui/IconButton.svelte";
@@ -8,12 +8,12 @@
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: NumberSpec | SliderSpec;
 		onchange?: (value: number) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as NumberSpec | SliderSpec);
+	const sp = $derived(spec);
 	const min = $derived(sp.min ?? 0);
 	const max = $derived(sp.max ?? 100);
 	const step = $derived(sp.step ?? 1);
diff --git a/web/src/lib/components/fields/schema/SegmentedControl.svelte b/web/src/lib/components/fields/schema/SegmentedControl.svelte
index b314121..0728fda 100644
--- a/web/src/lib/components/fields/schema/SegmentedControl.svelte
+++ b/web/src/lib/components/fields/schema/SegmentedControl.svelte
@@ -2,19 +2,19 @@
 	import Control from "./Control.svelte";
 	import Segmented from "$lib/components/ui/Segmented.svelte";
 	import { optionLabel } from "$lib/i18n/schema-tool-strings";
-	import type { FieldSpec, SegmentedSpec } from "$lib/registry-schema";
+	import type { SegmentedSpec } from "$lib/registry-schema";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: SegmentedSpec;
 		toolId: string;
 		fieldId: string;
 		onchange?: (value: string) => void;
 	}
 	let { label, value, spec, toolId, fieldId, onchange }: Props = $props();
 
-	const sp = $derived(spec as SegmentedSpec);
+	const sp = $derived(spec);
 	const current = $derived(
 		typeof value === "string" && sp.options.some((o) => o.value === value)
 			? value
diff --git a/web/src/lib/components/fields/schema/SelectControl.svelte b/web/src/lib/components/fields/schema/SelectControl.svelte
index f0d6847..df01d77 100644
--- a/web/src/lib/components/fields/schema/SelectControl.svelte
+++ b/web/src/lib/components/fields/schema/SelectControl.svelte
@@ -1,19 +1,19 @@
 <script lang="ts">
 	import { optionLabel } from "$lib/i18n/schema-tool-strings";
-	import type { FieldSpec, SelectSpec } from "$lib/registry-schema";
+	import type { SelectSpec } from "$lib/registry-schema";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: SelectSpec;
 		toolId: string;
 		fieldId: string;
 		onchange?: (value: string) => void;
 	}
 	let { label, value, spec, toolId, fieldId, onchange }: Props = $props();
 
-	const sp = $derived(spec as SelectSpec);
+	const sp = $derived(spec);
 	const current = $derived(
 		typeof value === "string" && sp.options.some((o) => o.value === value)
 			? value
diff --git a/web/src/lib/components/fields/schema/TextControl.svelte b/web/src/lib/components/fields/schema/TextControl.svelte
index 55457e5..7205e82 100644
--- a/web/src/lib/components/fields/schema/TextControl.svelte
+++ b/web/src/lib/components/fields/schema/TextControl.svelte
@@ -1,16 +1,16 @@
 <script lang="ts">
-	import type { FieldSpec, TextSpec } from "$lib/registry-schema";
+	import type { TextSpec } from "$lib/registry-schema";
 	import Control from "./Control.svelte";
 
 	interface Props {
 		label: string;
 		value: unknown;
-		spec: FieldSpec;
+		spec: TextSpec;
 		onchange?: (value: string) => void;
 	}
 	let { label, value, spec, onchange }: Props = $props();
 
-	const sp = $derived(spec as TextSpec);
+	const sp = $derived(spec);
 	const current = $derived(typeof value === "string" ? value : sp.default);
 </script>
 
diff --git a/web/src/lib/components/schema/SchemaFields.svelte b/web/src/lib/components/schema/SchemaFields.svelte
index f1f5316..93cd3e7 100644
--- a/web/src/lib/components/schema/SchemaFields.svelte
+++ b/web/src/lib/components/schema/SchemaFields.svelte
@@ -1,8 +1,23 @@
 <script lang="ts">
 	import type {
+		CheckboxSpec,
+		ColorListSpec,
+		ColorPairSpec,
+		ColorSpec,
 		Dimension,
+		DimensionSpec,
 		FieldSpec,
 		FieldSpecKind,
+		FontStyleSpec,
+		GradientSpec,
+		NumberSpec,
+		OffsetSpec,
+		PlateSpec,
+		Position9Spec,
+		SegmentedSpec,
+		SelectSpec,
+		SliderSpec,
+		TextSpec,
 		ToolSchema,
 	} from "$lib/registry-schema";
 	import { effectiveMax, resolveLayoutGroups } from "$lib/registry-schema";
@@ -36,22 +51,34 @@
 		onchange?: (value: unknown, axis?: "width" | "height" | "both") => void;
 	}
 
+	// The kind key of FIELDS guarantees the spec subtype at runtime (fieldSpecs
+	// map in registry-schema); the cast lives once here, so each control
+	// declares its exact spec type instead of casting internally.
+	type ControlFor<S extends FieldSpec> = Component<
+		Omit<FieldControlProps, "spec"> & { spec: S }
+	>;
+	function controlFor<S extends FieldSpec>(
+		c: ControlFor<S>,
+	): Component<FieldControlProps> {
+		return c as unknown as Component<FieldControlProps>;
+	}
+
 	const FIELDS: Record<FieldSpecKind, Component<FieldControlProps>> = {
-		number: RangeControl,
-		slider: RangeControl,
-		color: ColorControl,
-		"color-pair": ColorPairControl,
-		colors: ColorsControl,
-		select: SelectControl,
-		segmented: SegmentedControl,
-		checkbox: CheckboxControl,
-		text: TextControl,
-		dimension: DimensionField,
-		offset: OffsetControl,
-		position9: PositionControl,
-		"font-style": FontStyleControl,
-		plate: PlateControl,
-		gradient: GradientControl,
+		number: controlFor<NumberSpec | SliderSpec>(RangeControl),
+		slider: controlFor<NumberSpec | SliderSpec>(RangeControl),
+		color: controlFor<ColorSpec>(ColorControl),
+		"color-pair": controlFor<ColorPairSpec>(ColorPairControl),
+		colors: controlFor<ColorListSpec>(ColorsControl),
+		select: controlFor<SelectSpec>(SelectControl),
+		segmented: controlFor<SegmentedSpec>(SegmentedControl),
+		checkbox: controlFor<CheckboxSpec>(CheckboxControl),
+		text: controlFor<TextSpec>(TextControl),
+		dimension: controlFor<DimensionSpec>(DimensionField),
+		offset: controlFor<OffsetSpec>(OffsetControl),
+		position9: controlFor<Position9Spec>(PositionControl),
+		"font-style": controlFor<FontStyleSpec>(FontStyleControl),
+		plate: controlFor<PlateSpec>(PlateControl),
+		gradient: controlFor<GradientSpec>(GradientControl),
 	};
 
 	interface Props {
diff --git a/web/src/lib/components/schema/SchemaToolView.svelte b/web/src/lib/components/schema/SchemaToolView.svelte
index 8da5a8d..6648a99 100644
--- a/web/src/lib/components/schema/SchemaToolView.svelte
+++ b/web/src/lib/components/schema/SchemaToolView.svelte
@@ -42,7 +42,6 @@
 		applySourceDefaults,
 		clampSourceAwareMaxes,
 		sanitizeSchemaParams,
-		type ToolSchema,
 	} from "$lib/registry-schema";
 	import { onMount } from "svelte";
 	import { SvelteSet } from "svelte/reactivity";
@@ -65,9 +64,7 @@
 	}
 	let { page, tool, chainId = undefined }: Props = $props();
 
-	const schema = $derived(
-		tool.schema as ToolSchema<Record<string, unknown>> | undefined,
-	);
+	const schema = $derived(tool.schema);
 
 	const inputMode = $derived(tool.input);
 
@@ -471,14 +468,17 @@
 						onadd={(id) => replaceStepTool(i, id)}
 					/>
 				{/snippet}
-				<SchemaFields
-					schema={toolSchemaOf(step)}
-					values={step.params}
-					toolId={step.id}
-					sourceDims={i === 0 ? (source ?? undefined) : stepDims[i - 1]}
-					onchange={(id, v, axis) => setStepValue(i, id, v, axis)}
-					onreset={() => resetStep(i)}
-				/>
+				{@const stepSchema = toolSchemaOf(step)}
+				{#if stepSchema}
+					<SchemaFields
+						schema={stepSchema}
+						values={step.params}
+						toolId={step.id}
+						sourceDims={i === 0 ? (source ?? undefined) : stepDims[i - 1]}
+						onchange={(id, v, axis) => setStepValue(i, id, v, axis)}
+						onreset={() => resetStep(i)}
+					/>
+				{/if}
 			</StepCard>
 		{/snippet}
 
diff --git a/web/src/lib/components/schema/schema-tool-state.svelte.ts b/web/src/lib/components/schema/schema-tool-state.svelte.ts
index 5c63ba0..7f875e8 100644
--- a/web/src/lib/components/schema/schema-tool-state.svelte.ts
+++ b/web/src/lib/components/schema/schema-tool-state.svelte.ts
@@ -12,7 +12,6 @@ import {
 	defaultSchemaParams,
 	withAspectLock,
 	type Dimension,
-	type ToolSchema,
 } from "$lib/registry-schema";
 import { SvelteMap, SvelteSet } from "svelte/reactivity";
 
@@ -28,7 +27,7 @@ interface StepsState {
 }
 
 export function toolSchemaOf(step: ChainStep) {
-	return getTool(step.id)?.schema as ToolSchema<Record<string, unknown>>;
+	return getTool(step.id)?.schema;
 }
 
 function setStepValue(
@@ -79,7 +78,8 @@ function setStepValue(
 			}
 		}
 	}
-	const clamped = dims ? clampSourceAwareMaxes(stepSchema, next, dims) : next;
+	const clamped =
+		dims && stepSchema ? clampSourceAwareMaxes(stepSchema, next, dims) : next;
 	s.steps = s.steps.with(index, { ...step, params: clamped });
 }
 
diff --git a/web/src/lib/executor/executor.ts b/web/src/lib/executor/executor.ts
index a6ddfa6..19d7bc3 100644
--- a/web/src/lib/executor/executor.ts
+++ b/web/src/lib/executor/executor.ts
@@ -30,6 +30,8 @@ type PendingRequest = {
 };
 
 function defaultWorkerFactory(): WorkerLike {
+	// Worker's onerror is typed with ErrorEvent while WorkerLike expects Event;
+	// the DOM lib types are incompatible, hence the double cast.
 	return new Worker(new URL("./executor.worker.ts", import.meta.url), {
 		type: "module",
 	}) as unknown as WorkerLike;