feat(server): packaging Docker Compose et push Gitea Registry (ticket #52)

Ajoute le Dockerfile multi-stage (build dart:stable, runtime
debian:bookworm-slim avec ca-certificates, exécutable AOT compilé), le
docker-compose.yaml (API + Postgres avec healthcheck et
depends_on: service_healthy), .env.example, .dockerignore et les
scripts scripts/docker-entrypoint.sh (migration au démarrage) et
scripts/push-gitea-image.sh (aucun identifiant en dur, mot de passe
via --password-stdin). dart analyze clean, dart test 24/24 vert,
`docker compose config` valide (syntaxe, interpolation de variables,
healthcheck). Dockerfile et scripts relus manuellement et jugés
corrects ; pas de docker build/compose up réel faute d'accès au
daemon Docker dans ce sandbox.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/README.md

@@ -125,13 +125,73 @@ without failing the whole request. Accepting a share creates a new
 `409` for revoked or already answered shares, while missing shares or recipients
 return `404`.
 
+## Docker Deployment
+
+Ticket #52 adds Docker packaging for a headless Linux deployment. TLS is not
+handled by the API container: terminate HTTPS in an external reverse proxy and
+forward traffic to the Docker host on `API_PORT`.
+
+Create a local environment file:
+
+```bash
+cp .env.example .env
+```
+
+Edit `.env` before deployment:
+
+- `API_BIND_ADDRESS`: Docker host interface to publish. Use `0.0.0.0` for LAN
+  access by the external reverse proxy, or a specific host IP to restrict the
+  bind address.
+- `API_PORT`: host port exposed for the reverse proxy.
+- `POSTGRES_DB`, `POSTGRES_USER`, `POSTGRES_PASSWORD`: PostgreSQL bootstrap
+  values.
+- `DATABASE_HOST`, `DATABASE_PORT`, `DATABASE_NAME`, `DATABASE_USER`,
+  `DATABASE_PASSWORD`: database connection used by the API. With the provided
+  Compose file, `DATABASE_HOST=postgres`.
+- `MIGRATE_ON_STARTUP`: when `true`, the API container applies SQL migrations
+  before starting the server.
+
+Start the stack from `server/`:
+
+```bash
+docker compose up -d --build
+```
+
+The `api` service waits for the PostgreSQL healthcheck, runs `/app/bin/migrate`,
+then launches `/app/bin/server`. Migrations are copied into the image under
+`/app/migrations`.
+
+To inspect the fully interpolated Compose configuration:
+
+```bash
+docker compose config
+```
+
+## Gitea Registry
+
+Build and push the server image to a Gitea Container Registry with no registry
+or credential value stored in the repository:
+
+```bash
+GITEA_REGISTRY=gitea.example.com \
+GITEA_OWNER=my-org \
+GITEA_IMAGE_NAME=gametime-server \
+GITEA_IMAGE_TAG=latest \
+GITEA_USERNAME=my-user \
+GITEA_TOKEN='replace-with-token' \
+./scripts/push-gitea-image.sh
+```
+
+`GITEA_IMAGE_TAG` defaults to `latest` when omitted. The script uses
+`docker login --password-stdin` so the token is not printed by the command line.
+
 ## Scope
 
 Ticket #47 only scaffolds the Dart server, the hexagonal directory layout and
 the `/health` endpoint. Ticket #49 adds the first PostgreSQL schema. Ticket #48
 adds authentication. Ticket #50 adds sync. Ticket #51 adds targeted sharing.
+Ticket #52 adds Docker Compose packaging and Gitea registry publishing.
 
 Upcoming tickets will fill the empty adapters and use cases:
 
-- #52: Docker and registry packaging.
 - #53: API, contract and integration tests.