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

.gitattributes

@@ -0,0 +1,13 @@
+# Exclude dev files from distribution ZIP
+node_modules/          export-ignore
+docker/                export-ignore
+resources/js/modules/  export-ignore
+.github/               export-ignore
+.gitattributes         export-ignore
+.gitignore             export-ignore
+package.json           export-ignore
+package-lock.json      export-ignore
+rollup.config.js       export-ignore
+composer.json          export-ignore
+CLAUDE.md              export-ignore
+todo/                  export-ignore