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.

Dockerfile

@@ -0,0 +1,27 @@
+syntax=docker/dockerfile:1
+
+FROM golang:1.25-alpine AS build
+WORKDIR /src
+ENV CGO_ENABLED=0
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+ARG VERSION=dev
+RUN go build -trimpath -ldflags "-s -w -X main.version=${VERSION}" -o /out/inventree ./cmd/inventree
+
+FROM alpine:3.20
+RUN apk add --no-cache ca-certificates tzdata && \
+    addgroup -S inventree && adduser -S inventree -G inventree
+WORKDIR /app
+COPY --from=build /out/inventree /usr/local/bin/inventree
+RUN mkdir -p /app/data && chown -R inventree:inventree /app/data
+
+USER inventree
+VOLUME ["/app/data"]
+EXPOSE 8080
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s CMD wget -qO- http://127.0.0.1:8080/healthz || exit 1
+
+ENTRYPOINT ["inventree"]
+CMD ["serve", "-addr", ":8080", "-db", "/app/data/inventree.db"]