feat: implement versioning and release management in the project

- Added automatic versioning based on git tags using semantic-release in Gitea Actions.
- Introduced new API endpoints `GET /version` and `GET /v1/version` to expose build metadata.
- Updated Docker build process to include version and build time information in Go binaries.
- Enhanced documentation with details on release processes and versioning guidelines.
- Integrated version display in the web application for better user visibility.

deploy/docker/README.md

@@ -2,7 +2,11 @@
 
 ## CI (Gitea Actions)
 
-Сборка образов — **`docker buildx bake`** (`deploy/docker/docker-bake.hcl`), а не матрица из восьми отдельных `docker build`.
+Сборка образов — **`docker buildx bake`** (`deploy/docker/docker-bake.hcl`), не отдельные `docker build`.
+
+**Publish:** push git-тега `vX.Y.Z` запускает [.gitea/workflows/publish.yaml](../.gitea/workflows/publish.yaml) — образы с semver-тегом, `latest`, `sha-*`. Переменная `VERSION` из тега попадает в Go-бинарники через `-ldflags`.
+
+Локально BuildKit также кэширует `/go/pkg/mod` и `~/.cache/go-build` через `RUN --mount=type=cache`.
 
 | Было | Стало |
 |------|--------|
@@ -31,6 +35,8 @@ cd deploy/docker
 export REGISTRY=git.shts.su/<owner>
 export IMAGE_TAG=latest
 export SHORT_SHA=$(git rev-parse --short HEAD)
+export VERSION=dev
+export BUILD_TIME=
 sh write-bake-override.sh
 docker buildx bake --allow=fs.read=../.. -f docker-bake.hcl -f docker-bake.override.hcl go-images
 docker buildx bake --allow=fs.read=../.. -f docker-bake.hcl -f docker-bake.override.hcl web-images