Initial commit: webtrees full diagram chart module

Interactive SVG family tree visualization using ELK (Sugiyama) for
layout and D3 for rendering. Shows ancestors, descendants, and siblings
in a single diagram with orthogonal bus-line connectors.

Features:
- Bidirectional tree traversal (ancestors + descendants + siblings)
- Generation-aligned layout with post-processing Y-snap
- Person cards with photos, names, dates, and hover bio cards
- "More ancestors" indicator for persons with hidden parents
- Pan/zoom navigation
- Docker dev environment

resources/js/modules/lib/tree/ancestor-tree.js

@@ -0,0 +1,31 @@
+/**
+ * Ancestor tree rendering — draws ancestor nodes and links upward from root.
+ */
+import { renderPersonCard } from "../chart/box.js";
+import { drawElbowLink } from "./link-drawer.js";
+
+/**
+ * Render the ancestor tree nodes and links.
+ *
+ * @param {d3.Selection} canvas - The SVG canvas group
+ * @param {Array} nodes - Ancestor hierarchy nodes (from computeLayout)
+ * @param {Array} links - Ancestor hierarchy links
+ * @param {Configuration} config
+ * @param {Function} onNodeClick
+ * @param {string} containerSelector
+ */
+export function renderAncestorTree(canvas, nodes, links, config, onNodeClick, containerSelector) {
+    // Draw links first (behind nodes)
+    const linkGroup = canvas.append("g").attr("class", "ancestor-links");
+
+    for (const link of links) {
+        drawElbowLink(linkGroup, link.source, link.target, "ancestor-link", config);
+    }
+
+    // Draw nodes
+    const nodeGroup = canvas.append("g").attr("class", "ancestor-nodes");
+
+    for (const node of nodes) {
+        renderPersonCard(nodeGroup, node, config, onNodeClick, containerSelector);
+    }
+}