Place the backend Dockerfile at repo root as Dockerfile.backend so
the build context includes .git, giving git describe access for
version stamping. Fix .gitignore pattern to anchor /netwatch-server
so it does not exclude cmd/netwatch-server/. Remove .git from
.dockerignore. Update CI workflow and backend Makefile docker target.
Update base image from golang:1.24-alpine to golang:1.25-alpine
to match go.mod requirement. Install golangci-lint by pinned commit
hash so make check passes inside the container. Update runtime
image to alpine:3.23.
Add .gitea/workflows/check.yml that builds both the root and
backend Docker images on push. Add LICENSE and README.md to the
backend subproject to match repo standards.
Introduce the Go backend (netwatch-server) with an HTTP API that
accepts telemetry reports and persists them as zstd-compressed JSONL
files. Reports are buffered in memory and flushed to disk when the
buffer reaches 10 MiB or every 60 seconds.
