feat: Archivum skeleton — Go/GraphQL backend + Vue 3 PWA frontend

Full project scaffold: multi-stage Dockerfile (ARM64/AMD64), AsciiDoc↔TipTap
bridge, Setup Wizard, CodeMirror source editor, Git-backed storage layer,
LDAP+JWT auth skeleton, Tailwind mobile-first layout, and VS Code build/push
tasks targeting registry at 192.168.0.19:5000.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,31 @@
+# Go
+backend/vendor/
+backend/*.exe
+backend/*.test
+backend/archivum
+
+# Frontend
+frontend/node_modules/
+frontend/dist/
+frontend/.env
+frontend/.env.local
+
+# Docker local data
+docker/data/
+
+# Generated GraphQL code
+backend/internal/graph/generated.go
+backend/internal/graph/models_gen.go
+
+# Config (never commit secrets)
+config.json
+settings.json
+*.db
+
+# OS
+.DS_Store
+Thumbs.db
+
+# IDE
+.idea/
+*.swp