Initial implementation of inventree

A small IT asset inventory system built around a nested folder tree,
matching the project brief: Go + html/template + Bootstrap 5 + vanilla JS,
SQLite storage (WAL, FKs, migrations), embedded templates/static assets,
single compiled binary.

- AJAX-driven inventory tree: lazy-loaded folder expansion with per-user
  persisted expand state, drag-and-drop move for folders/assets, safe
  delete-with-relocate-or-cascade confirmation, search with breadcrumbs.
- Assets: CRUD, duplicate, move, auto-generated IT-000001-style IDs,
  CSV import (with optional folder auto-create) and export.
- Admin-defined item types with custom fields (text/long_text/number/date/
  boolean/dropdown/url/ip_address).
- Configurable statuses, session-based auth (bcrypt, secure cookies),
  admin/user roles, user management.
- CLI: serve, version, database migrate, database backup; /healthz;
  graceful shutdown; Dockerfile/docker-compose/systemd unit; Go test suite.

deploy/inventree.service

@@ -0,0 +1,22 @@
+[Unit]
+Description=inventree - IT asset inventory
+After=network.target
+
+[Service]
+Type=simple
+User=inventree
+Group=inventree
+WorkingDirectory=/opt/inventree
+ExecStart=/opt/inventree/inventree serve -addr :8080 -db /opt/inventree/data/inventree.db
+Restart=on-failure
+RestartSec=2
+
+# Hardening (safe defaults for a small single-binary service)
+NoNewPrivileges=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/opt/inventree/data
+PrivateTmp=true
+
+[Install]
+WantedBy=multi-user.target