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.

internal/database/database_test.go

@@ -0,0 +1,76 @@
+package database_test
+
+import (
+	"path/filepath"
+	"testing"
+
+	"inventree/internal/database"
+)
+
+func TestOpenSetsPragmasAndMigrates(t *testing.T) {
+	dir := t.TempDir()
+	db, err := database.Open(filepath.Join(dir, "test.db"))
+	if err != nil {
+		t.Fatalf("open: %v", err)
+	}
+	defer db.Close()
+
+	var journalMode string
+	if err := db.QueryRow(`PRAGMA journal_mode`).Scan(&journalMode); err != nil {
+		t.Fatalf("query journal_mode: %v", err)
+	}
+	if journalMode != "wal" {
+		t.Fatalf("expected WAL journal mode, got %q", journalMode)
+	}
+
+	var fk int
+	if err := db.QueryRow(`PRAGMA foreign_keys`).Scan(&fk); err != nil {
+		t.Fatalf("query foreign_keys: %v", err)
+	}
+	if fk != 1 {
+		t.Fatalf("expected foreign_keys=1, got %d", fk)
+	}
+
+	var userCount int
+	if err := db.QueryRow(`SELECT COUNT(*) FROM users`).Scan(&userCount); err != nil {
+		t.Fatalf("query users: %v", err)
+	}
+	if userCount != 1 {
+		t.Fatalf("expected 1 seeded admin user, got %d", userCount)
+	}
+
+	var statusCount int
+	if err := db.QueryRow(`SELECT COUNT(*) FROM statuses`).Scan(&statusCount); err != nil {
+		t.Fatalf("query statuses: %v", err)
+	}
+	if statusCount != 5 {
+		t.Fatalf("expected 5 seeded statuses, got %d", statusCount)
+	}
+}
+
+func TestMigrateIsIdempotent(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "test.db")
+
+	db1, err := database.Open(path)
+	if err != nil {
+		t.Fatalf("first open: %v", err)
+	}
+	db1.Close()
+
+	// Re-opening (and re-migrating) an already-migrated database must not
+	// error or duplicate seed data.
+	db2, err := database.Open(path)
+	if err != nil {
+		t.Fatalf("second open: %v", err)
+	}
+	defer db2.Close()
+
+	var userCount int
+	if err := db2.QueryRow(`SELECT COUNT(*) FROM users`).Scan(&userCount); err != nil {
+		t.Fatalf("query users: %v", err)
+	}
+	if userCount != 1 {
+		t.Fatalf("expected still 1 seeded admin user after reopen, got %d", userCount)
+	}
+}