refactor(stammbaum): split StammbaumTree into Connectors + Node components (#692)

Extract the three SVG connector layers (+ the parent-link graph computation)
into StammbaumConnectors.svelte and the node <g> into StammbaumNode.svelte (which
now owns its own focus-ring state). StammbaumTree drops 546→308 lines and is now
an orchestrator: layout, gutter/reduced-motion state, viewBox, gestures, rail,
anchor. Rendered SVG is byte-identical, so the existing browser tests are
unchanged. Verified live: 62 nodes + 58 connector lines render, node-tap selects.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/lib/person/genealogy/StammbaumConnectors.svelte

@@ -0,0 +1,189 @@
+<script lang="ts">
+import { SvelteMap, SvelteSet } from 'svelte/reactivity';
+import { type Layout, NODE_W, NODE_H } from '$lib/person/genealogy/layout/buildLayout';
+import type { components } from '$lib/generated/api';
+
+type RelationshipDTO = components['schemas']['RelationshipDTO'];
+
+interface Props {
+	edges: RelationshipDTO[];
+	positions: Layout['positions'];
+}
+
+let { edges, positions }: Props = $props();
+
+function nodeCenter(id: string): { x: number; y: number } | null {
+	const p = positions.get(id);
+	if (!p) return null;
+	return { x: p.x + NODE_W / 2, y: p.y + NODE_H / 2 };
+}
+
+const parentEdges = $derived(edges.filter((e) => e.relationType === 'PARENT_OF'));
+const spouseEdges = $derived(edges.filter((e) => e.relationType === 'SPOUSE_OF'));
+
+function pairKey(a: string, b: string): string {
+	return a < b ? `${a}|${b}` : `${b}|${a}`;
+}
+
+type ParentLinks = {
+	// One entry per spouse-pair-with-children: drives the drop + sibling-bar
+	// + per-child vertical pattern in the SVG.
+	shared: { key: string; parentA: string; parentB: string; childIds: string[] }[];
+	// One entry per remaining parent → child edge (single parents, or the
+	// "second" parent edge when only one parent is in the spouse pair).
+	single: { key: string; parentId: string; childId: string }[];
+};
+
+const parentLinks = $derived.by<ParentLinks>(() => {
+	const spousePairs = new SvelteSet<string>();
+	for (const e of spouseEdges) {
+		spousePairs.add(pairKey(e.personId, e.relatedPersonId));
+	}
+
+	const childToParents = new SvelteMap<string, string[]>();
+	for (const e of parentEdges) {
+		const list = childToParents.get(e.relatedPersonId) ?? [];
+		list.push(e.personId);
+		childToParents.set(e.relatedPersonId, list);
+	}
+
+	const sharedMap = new SvelteMap<
+		string,
+		{ parentA: string; parentB: string; childIds: string[] }
+	>();
+	const single: ParentLinks['single'] = [];
+	for (const [childId, parents] of childToParents) {
+		const consumed = new SvelteSet<string>();
+		for (let i = 0; i < parents.length; i++) {
+			if (consumed.has(parents[i])) continue;
+			for (let j = i + 1; j < parents.length; j++) {
+				if (consumed.has(parents[j])) continue;
+				if (spousePairs.has(pairKey(parents[i], parents[j]))) {
+					const groupKey = pairKey(parents[i], parents[j]);
+					const existing = sharedMap.get(groupKey);
+					if (existing) {
+						existing.childIds.push(childId);
+					} else {
+						sharedMap.set(groupKey, {
+							parentA: parents[i],
+							parentB: parents[j],
+							childIds: [childId]
+						});
+					}
+					consumed.add(parents[i]);
+					consumed.add(parents[j]);
+					break;
+				}
+			}
+		}
+		for (const parentId of parents) {
+			if (consumed.has(parentId)) continue;
+			single.push({ key: `${parentId}->${childId}`, parentId, childId });
+		}
+	}
+
+	const shared: ParentLinks['shared'] = [];
+	for (const [key, group] of sharedMap) shared.push({ key, ...group });
+	return { shared, single };
+});
+</script>
+
+<!-- Shared parent-pair → children: drop from spouse midpoint to a sibling
+     bar, then short verticals from the bar to each child top. -->
+{#each parentLinks.shared as group (group.key)}
+	{@const aCenter = nodeCenter(group.parentA)}
+	{@const bCenter = nodeCenter(group.parentB)}
+	{@const childCenters = group.childIds
+		.map((id) => nodeCenter(id))
+		.filter((c): c is { x: number; y: number } => c !== null)}
+	{#if aCenter && bCenter && childCenters.length > 0}
+		{@const midX = (aCenter.x + bCenter.x) / 2}
+		{@const parentBottomY = aCenter.y + NODE_H / 2}
+		{@const childTopY = childCenters[0].y - NODE_H / 2}
+		{@const barY = (parentBottomY + childTopY) / 2}
+		{@const xs = childCenters.map((c) => c.x)}
+		{@const minX = Math.min(midX, ...xs)}
+		{@const maxX = Math.max(midX, ...xs)}
+		<line
+			x1={midX}
+			y1={parentBottomY}
+			x2={midX}
+			y2={barY}
+			stroke="var(--c-primary)"
+			stroke-width="1.5"
+		/>
+		{#if minX !== maxX}
+			<line x1={minX} y1={barY} x2={maxX} y2={barY} stroke="var(--c-primary)" stroke-width="1.5" />
+		{/if}
+		{#each childCenters as cc, i (group.childIds[i])}
+			<line
+				x1={cc.x}
+				y1={barY}
+				x2={cc.x}
+				y2={childTopY}
+				stroke="var(--c-primary)"
+				stroke-width="1.5"
+			/>
+		{/each}
+	{/if}
+{/each}
+
+<!-- Single-parent → child connectors: parent bottom → bar → child top. -->
+{#each parentLinks.single as link (link.key)}
+	{@const parentCenter = nodeCenter(link.parentId)}
+	{@const childCenter = nodeCenter(link.childId)}
+	{#if parentCenter && childCenter}
+		{@const parentBottomY = parentCenter.y + NODE_H / 2}
+		{@const childTopY = childCenter.y - NODE_H / 2}
+		{@const barY = (parentBottomY + childTopY) / 2}
+		<line
+			x1={parentCenter.x}
+			y1={parentBottomY}
+			x2={parentCenter.x}
+			y2={barY}
+			stroke="var(--c-primary)"
+			stroke-width="1.5"
+		/>
+		{#if parentCenter.x !== childCenter.x}
+			<line
+				x1={parentCenter.x}
+				y1={barY}
+				x2={childCenter.x}
+				y2={barY}
+				stroke="var(--c-primary)"
+				stroke-width="1.5"
+			/>
+		{/if}
+		<line
+			x1={childCenter.x}
+			y1={barY}
+			x2={childCenter.x}
+			y2={childTopY}
+			stroke="var(--c-primary)"
+			stroke-width="1.5"
+		/>
+	{/if}
+{/each}
+
+<!-- Spouse connectors -->
+{#each spouseEdges as e (e.id)}
+	{@const aCenter = nodeCenter(e.personId)}
+	{@const bCenter = nodeCenter(e.relatedPersonId)}
+	{#if aCenter && bCenter}
+		<line
+			x1={aCenter.x}
+			y1={aCenter.y}
+			x2={bCenter.x}
+			y2={bCenter.y}
+			stroke="var(--c-primary)"
+			stroke-width="1.5"
+			stroke-dasharray={e.toYear ? '4 4' : undefined}
+		/>
+		<circle
+			cx={(aCenter.x + bCenter.x) / 2}
+			cy={(aCenter.y + bCenter.y) / 2}
+			r="6"
+			fill="var(--c-primary)"
+		/>
+	{/if}
+{/each}

frontend/src/lib/person/genealogy/StammbaumNode.svelte

@@ -0,0 +1,90 @@
+<script lang="ts">
+import { NODE_W, NODE_H } from '$lib/person/genealogy/layout/buildLayout';
+import type { components } from '$lib/generated/api';
+
+type PersonNodeDTO = components['schemas']['PersonNodeDTO'];
+
+interface Props {
+	node: PersonNodeDTO;
+	pos: { x: number; y: number };
+	selected: boolean;
+	onSelect: (id: string) => void;
+}
+
+let { node, pos, selected, onSelect }: Props = $props();
+
+// Each node owns its own focus-ring state (the focus ring is decorative; the
+// `<g role="button">` is the real focus target).
+let focused = $state(false);
+
+function handleKey(event: KeyboardEvent) {
+	if (event.key === 'Enter' || event.key === ' ') {
+		event.preventDefault();
+		onSelect(node.id);
+	}
+}
+
+const datesLabel = $derived(
+	node.birthYear || node.deathYear ? `, ${node.birthYear ?? '?'}–${node.deathYear ?? ''}` : ''
+);
+</script>
+
+<g
+	role="button"
+	tabindex="0"
+	aria-label="{node.displayName}{datesLabel}"
+	aria-expanded={selected}
+	transform="translate({pos.x}, {pos.y})"
+	onclick={() => onSelect(node.id)}
+	onkeydown={handleKey}
+	onfocus={() => (focused = true)}
+	onblur={() => (focused = false)}
+	class="cursor-pointer focus:outline-none"
+>
+	{#if focused}
+		<rect
+			x="-3"
+			y="-3"
+			width={NODE_W + 6}
+			height={NODE_H + 6}
+			rx="6"
+			fill="none"
+			stroke="var(--c-focus-ring)"
+			stroke-width="2"
+		/>
+	{/if}
+	<rect
+		width={NODE_W}
+		height={NODE_H}
+		rx="4"
+		fill={selected ? 'var(--c-primary)' : 'var(--c-surface)'}
+		stroke="var(--c-primary)"
+		stroke-width="1.5"
+	/>
+	{#if selected}
+		<rect width="4" height={NODE_H} rx="2" fill="var(--c-accent)" />
+	{/if}
+	<text
+		x={NODE_W / 2}
+		y={NODE_H / 2 - 6}
+		text-anchor="middle"
+		font-family="serif"
+		font-size="16"
+		fill={selected ? 'var(--c-primary-fg)' : 'var(--c-ink)'}
+	>
+		{node.displayName}
+	</text>
+	{#if node.birthYear || node.deathYear}
+		<text
+			x={NODE_W / 2}
+			y={NODE_H / 2 + 12}
+			text-anchor="middle"
+			font-family="sans-serif"
+			font-size="12"
+			fill={selected ? 'var(--c-primary-fg)' : 'var(--c-ink-3)'}
+			opacity={selected ? 0.75 : 1}
+		>
+			{node.birthYear ?? '?'}–{node.deathYear ?? ''}
+		</text>
+	{/if}
+</g>

frontend/src/lib/person/genealogy/StammbaumTree.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
 import { untrack, onMount } from 'svelte';
-import { SvelteMap, SvelteSet } from 'svelte/reactivity';
+import { SvelteMap } from 'svelte/reactivity';
 import type { components } from '$lib/generated/api';
 import {
 	buildLayout,
@@ -19,6 +19,8 @@ import {
 } from '$lib/person/genealogy/panZoom';
 import { panZoomGestures } from '$lib/person/genealogy/panZoomGestures';
 import StammbaumGenerationRail from '$lib/person/genealogy/StammbaumGenerationRail.svelte';
+import StammbaumConnectors from '$lib/person/genealogy/StammbaumConnectors.svelte';
+import StammbaumNode from '$lib/person/genealogy/StammbaumNode.svelte';
 
 type PersonNodeDTO = components['schemas']['PersonNodeDTO'];
 type RelationshipDTO = components['schemas']['RelationshipDTO'];
@@ -209,15 +211,6 @@ $effect(() => {
 	});
 });
 
-let focusedId = $state<string | null>(null);
-
-function handleNodeKey(event: KeyboardEvent, id: string) {
-	if (event.key === 'Enter' || event.key === ' ') {
-		event.preventDefault();
-		onSelect(id);
-	}
-}
-
 // Canvas-level keyboard: `+`/`-` zoom by the fixed step (OQ-002), arrows pan by
 // a tenth of the visible extent. Nodes keep their own Enter/Space selection.
 function handleCanvasKey(event: KeyboardEvent) {
@@ -249,75 +242,6 @@ function handleCanvasKey(event: KeyboardEvent) {
 	}
 	event.preventDefault();
 }
-
-const parentEdges = $derived(edges.filter((e) => e.relationType === 'PARENT_OF'));
-const spouseEdges = $derived(edges.filter((e) => e.relationType === 'SPOUSE_OF'));
-
-function pairKey(a: string, b: string): string {
-	return a < b ? `${a}|${b}` : `${b}|${a}`;
-}
-
-type ParentLinks = {
-	// One entry per spouse-pair-with-children: drives the drop + sibling-bar
-	// + per-child vertical pattern in the SVG.
-	shared: { key: string; parentA: string; parentB: string; childIds: string[] }[];
-	// One entry per remaining parent → child edge (single parents, or the
-	// "second" parent edge when only one parent is in the spouse pair).
-	single: { key: string; parentId: string; childId: string }[];
-};
-
-const parentLinks = $derived.by<ParentLinks>(() => {
-	const spousePairs = new SvelteSet<string>();
-	for (const e of spouseEdges) {
-		spousePairs.add(pairKey(e.personId, e.relatedPersonId));
-	}
-
-	const childToParents = new SvelteMap<string, string[]>();
-	for (const e of parentEdges) {
-		const list = childToParents.get(e.relatedPersonId) ?? [];
-		list.push(e.personId);
-		childToParents.set(e.relatedPersonId, list);
-	}
-
-	const sharedMap = new SvelteMap<
-		string,
-		{ parentA: string; parentB: string; childIds: string[] }
-	>();
-	const single: ParentLinks['single'] = [];
-	for (const [childId, parents] of childToParents) {
-		const consumed = new SvelteSet<string>();
-		for (let i = 0; i < parents.length; i++) {
-			if (consumed.has(parents[i])) continue;
-			for (let j = i + 1; j < parents.length; j++) {
-				if (consumed.has(parents[j])) continue;
-				if (spousePairs.has(pairKey(parents[i], parents[j]))) {
-					const groupKey = pairKey(parents[i], parents[j]);
-					const existing = sharedMap.get(groupKey);
-					if (existing) {
-						existing.childIds.push(childId);
-					} else {
-						sharedMap.set(groupKey, {
-							parentA: parents[i],
-							parentB: parents[j],
-							childIds: [childId]
-						});
-					}
-					consumed.add(parents[i]);
-					consumed.add(parents[j]);
-					break;
-				}
-			}
-		}
-		for (const parentId of parents) {
-			if (consumed.has(parentId)) continue;
-			single.push({ key: `${parentId}->${childId}`, parentId, childId });
-		}
-	}
-
-	const shared: ParentLinks['shared'] = [];
-	for (const [key, group] of sharedMap) shared.push({ key, ...group });
-	return { shared, single };
-});
 </script>
 
 <!-- Relative wrapper so the pinned generation rail can overlay the canvas. -->
@@ -364,180 +288,18 @@ const parentLinks = $derived.by<ParentLinks>(() => {
 			{/each}
 		{/if}
 
-		<!-- Shared parent-pair → children: drop from spouse midpoint to a sibling
-	     bar, then short verticals from the bar to each child top. -->
-		{#each parentLinks.shared as group (group.key)}
-			{@const aCenter = nodeCenter(group.parentA)}
-			{@const bCenter = nodeCenter(group.parentB)}
-			{@const childCenters = group.childIds
-			.map((id) => nodeCenter(id))
-			.filter((c): c is { x: number; y: number } => c !== null)}
-			{#if aCenter && bCenter && childCenters.length > 0}
-				{@const midX = (aCenter.x + bCenter.x) / 2}
-				{@const parentBottomY = aCenter.y + NODE_H / 2}
-				{@const childTopY = childCenters[0].y - NODE_H / 2}
-				{@const barY = (parentBottomY + childTopY) / 2}
-				{@const xs = childCenters.map((c) => c.x)}
-				{@const minX = Math.min(midX, ...xs)}
-				{@const maxX = Math.max(midX, ...xs)}
-				<line
-					x1={midX}
-					y1={parentBottomY}
-					x2={midX}
-					y2={barY}
-					stroke="var(--c-primary)"
-					stroke-width="1.5"
-				/>
-				{#if minX !== maxX}
-					<line
-						x1={minX}
-						y1={barY}
-						x2={maxX}
-						y2={barY}
-						stroke="var(--c-primary)"
-						stroke-width="1.5"
-					/>
-				{/if}
-				{#each childCenters as cc, i (group.childIds[i])}
-					<line
-						x1={cc.x}
-						y1={barY}
-						x2={cc.x}
-						y2={childTopY}
-						stroke="var(--c-primary)"
-						stroke-width="1.5"
-					/>
-				{/each}
-			{/if}
-		{/each}
-
-		<!-- Single-parent → child connectors: parent bottom → bar → child top. -->
-		{#each parentLinks.single as link (link.key)}
-			{@const parentCenter = nodeCenter(link.parentId)}
-			{@const childCenter = nodeCenter(link.childId)}
-			{#if parentCenter && childCenter}
-				{@const parentBottomY = parentCenter.y + NODE_H / 2}
-				{@const childTopY = childCenter.y - NODE_H / 2}
-				{@const barY = (parentBottomY + childTopY) / 2}
-				<line
-					x1={parentCenter.x}
-					y1={parentBottomY}
-					x2={parentCenter.x}
-					y2={barY}
-					stroke="var(--c-primary)"
-					stroke-width="1.5"
-				/>
-				{#if parentCenter.x !== childCenter.x}
-					<line
-						x1={parentCenter.x}
-						y1={barY}
-						x2={childCenter.x}
-						y2={barY}
-						stroke="var(--c-primary)"
-						stroke-width="1.5"
-					/>
-				{/if}
-				<line
-					x1={childCenter.x}
-					y1={barY}
-					x2={childCenter.x}
-					y2={childTopY}
-					stroke="var(--c-primary)"
-					stroke-width="1.5"
-				/>
-			{/if}
-		{/each}
-
-		<!-- Spouse connectors -->
-		{#each spouseEdges as e (e.id)}
-			{@const aCenter = nodeCenter(e.personId)}
-			{@const bCenter = nodeCenter(e.relatedPersonId)}
-			{#if aCenter && bCenter}
-				<line
-					x1={aCenter.x}
-					y1={aCenter.y}
-					x2={bCenter.x}
-					y2={bCenter.y}
-					stroke="var(--c-primary)"
-					stroke-width="1.5"
-					stroke-dasharray={e.toYear ? '4 4' : undefined}
-				/>
-				<circle
-					cx={(aCenter.x + bCenter.x) / 2}
-					cy={(aCenter.y + bCenter.y) / 2}
-					r="6"
-					fill="var(--c-primary)"
-				/>
-			{/if}
-		{/each}
+		<StammbaumConnectors edges={edges} positions={layout.positions} />
 
 		<!-- Nodes -->
 		{#each nodes as node (node.id)}
 			{@const pos = layout.positions.get(node.id)}
 			{#if pos}
-				{@const isSelected = selectedId === node.id}
-				{@const isFocused = focusedId === node.id}
-				<g
-					role="button"
-					tabindex="0"
-					aria-label="{node.displayName}{node.birthYear || node.deathYear
-					? `, ${node.birthYear ?? '?'}–${node.deathYear ?? ''}`
-					: ''}"
-					aria-expanded={isSelected}
-					transform="translate({pos.x}, {pos.y})"
-					onclick={() => onSelect(node.id)}
-					onkeydown={(e) => handleNodeKey(e, node.id)}
-					onfocus={() => (focusedId = node.id)}
-					onblur={() => (focusedId = null)}
-					class="cursor-pointer focus:outline-none"
-				>
-					{#if isFocused}
-						<rect
-							x="-3"
-							y="-3"
-							width={NODE_W + 6}
-							height={NODE_H + 6}
-							rx="6"
-							fill="none"
-							stroke="var(--c-focus-ring)"
-							stroke-width="2"
-						/>
-					{/if}
-					<rect
-						width={NODE_W}
-						height={NODE_H}
-						rx="4"
-						fill={isSelected ? 'var(--c-primary)' : 'var(--c-surface)'}
-						stroke="var(--c-primary)"
-						stroke-width="1.5"
-					/>
-					{#if isSelected}
-						<rect width="4" height={NODE_H} rx="2" fill="var(--c-accent)" />
-					{/if}
-					<text
-						x={NODE_W / 2}
-						y={NODE_H / 2 - 6}
-						text-anchor="middle"
-						font-family="serif"
-						font-size="16"
-						fill={isSelected ? 'var(--c-primary-fg)' : 'var(--c-ink)'}
-					>
-						{node.displayName}
-					</text>
-					{#if node.birthYear || node.deathYear}
-						<text
-							x={NODE_W / 2}
-							y={NODE_H / 2 + 12}
-							text-anchor="middle"
-							font-family="sans-serif"
-							font-size="12"
-							fill={isSelected ? 'var(--c-primary-fg)' : 'var(--c-ink-3)'}
-							opacity={isSelected ? 0.75 : 1}
-						>
-							{node.birthYear ?? '?'}–{node.deathYear ?? ''}
-						</text>
-					{/if}
-				</g>
+				<StammbaumNode
+					node={node}
+					pos={pos}
+					selected={selectedId === node.id}
+					onSelect={onSelect}
+				/>
 			{/if}
 		{/each}
 	</svg>