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

docker/docker-compose.yml

@@ -0,0 +1,43 @@
+services:
+  webtrees:
+    image: ghcr.io/nathanvaughn/webtrees:latest
+    ports:
+      - "8081:80"
+    environment:
+      PRETTY_URLS: "TRUE"
+      LANG: "en-US"
+      BASE_URL: "http://localhost:8081"
+      DB_TYPE: "mysql"
+      DB_HOST: "db"
+      DB_PORT: "3306"
+      DB_NAME: "webtrees"
+      DB_USER: "webtrees"
+      DB_PASS: "webtrees"
+    volumes:
+      - webtrees_data:/var/www/webtrees/data
+      - ..:/var/www/webtrees/modules_v4/full-diagram
+      - /home/alex/.local/src/webtrees_bocken_theme/BockenTheme:/var/www/webtrees/modules_v4/BockenTheme
+    depends_on:
+      db:
+        condition: service_healthy
+    restart: unless-stopped
+
+  db:
+    image: mariadb:11
+    environment:
+      MYSQL_ROOT_PASSWORD: root
+      MYSQL_DATABASE: webtrees
+      MYSQL_USER: webtrees
+      MYSQL_PASSWORD: webtrees
+    volumes:
+      - db_data:/var/lib/mysql
+    healthcheck:
+      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+    restart: unless-stopped
+
+volumes:
+  webtrees_data:
+  db_data: