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

package.json

@@ -0,0 +1,23 @@
+{
+    "name": "webtrees-full-diagram",
+    "version": "0.2.0",
+    "private": true,
+    "type": "module",
+    "scripts": {
+        "build": "rollup -c",
+        "watch": "rollup -c --watch",
+        "prepare": "npm run build"
+    },
+    "devDependencies": {
+        "@rollup/plugin-node-resolve": "^16.0.3",
+        "@rollup/plugin-terser": "^0.4.4",
+        "rollup": "^4.9.0"
+    },
+    "dependencies": {
+        "@rollup/plugin-commonjs": "^29.0.2",
+        "d3-selection": "^3.0.0",
+        "d3-transition": "^3.0.1",
+        "d3-zoom": "^3.0.0",
+        "elkjs": "^0.11.1"
+    }
+}