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/web/folderoptions.go

@@ -0,0 +1,56 @@
+package web
+
+import "context"
+
+// FolderOption is a flattened, indented folder choice for <select> dropdowns
+// (asset create/edit, move-to pickers).
+type FolderOption struct {
+	ID    int64
+	Path  string
+	Depth int
+}
+
+// folderOptions returns every folder as a flat, depth-first ordered list
+// with indentable depth, suitable for a folder-picker <select>.
+func (a *App) folderOptions(ctx context.Context) ([]FolderOption, error) {
+	all, err := a.Folders.All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	byParent := map[int64][]struct {
+		ID   int64
+		Name string
+	}{}
+	var top []struct {
+		ID   int64
+		Name string
+	}
+	for _, f := range all {
+		item := struct {
+			ID   int64
+			Name string
+		}{f.ID, f.Name}
+		if f.ParentID == nil {
+			top = append(top, item)
+		} else {
+			byParent[*f.ParentID] = append(byParent[*f.ParentID], item)
+		}
+	}
+
+	var out []FolderOption
+	var walk func(id int64, name, prefix string, depth int)
+	walk = func(id int64, name, prefix string, depth int) {
+		path := name
+		if prefix != "" {
+			path = prefix + " / " + name
+		}
+		out = append(out, FolderOption{ID: id, Path: path, Depth: depth})
+		for _, child := range byParent[id] {
+			walk(child.ID, child.Name, path, depth+1)
+		}
+	}
+	for _, t := range top {
+		walk(t.ID, t.Name, "", 0)
+	}
+	return out, nil
+}