feat(gitea): Stage 4 — hardened compose with OIDC-ready config + Keycloak CLI auth source

stacks/gitea/compose.yml — full production-grade env:
- Server posture: PROTOCOL=http (nginx terminates TLS), DOMAIN=git.wbd-rd.nl,
  DISABLE_SSH=true, INSTALL_LOCK=true (skip web wizard).
- Postgres backend (DB+role auto-provisioned by sql/config/init.d/).
- Local registration disabled; users provisioned via Keycloak OIDC with
  ENABLE_AUTO_REGISTRATION=true so first OIDC login auto-creates the
  matching local account (USERNAME=nickname, ACCOUNT_LINKING=auto).
- Mail stub via postfix on app network (ENABLED=false until postfix is up).
- Repos default to private.
- GITEA_OAUTH_* env vars are pass-through values consumed only by the
  post-deploy CLI step; gitea itself doesn't read them.

stacks/gitea/.env.example — DB connection, OAuth client ID/secret/discovery
URL, mail-from. Empty placeholders for secrets.

stacks/gitea/README.md — full Stage 5 deploy script:
  1. Fill GITEA_DB_PASSWORD + GITEA_OAUTH_CLIENT_SECRET in cloud/.env
  2. docker compose up -d gitea
  3. gitea admin user create --admin --random-password
  4. gitea admin auth add-oauth --provider openidConnect
     --auto-discover-url https://auth.wbd-rd.nl/realms/wbd/.well-known/openid-configuration
  5. Browse https://git.wbd-rd.nl/ → "Sign in with keycloak"

cloud/compose.yml — uncomment gitea include.
cloud/.env.example — add GITEA_DOMAIN, GITEA_OAUTH_*, GITEA_MAIL_FROM.

.gitignore line 2 (`.env`) already catches .env files at any depth
(verified with `git check-ignore`). Secrets won't be committed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

stacks/gitea/compose.yml

@@ -1,6 +1,8 @@
-# gitea — git server (cloud only)
-# Networks: app + data (uses sql stack as DB backend)
-# Ingress: HTTPS-only via nginx-proxy. No SSH port published.
+# gitea — self-hosted git server (cloud only)
+# Hostname: git.wbd-rd.nl (reverse-proxied via nginx-proxy; HTTP internally)
+# Networks: app (UI) + data (postgres backend)
+# Auth: SSO via Keycloak (`wbd` realm, client `gitea`)
+# OIDC auth source is added via CLI post-deploy — see README.
 
 services:
   gitea:
@@ -8,16 +10,58 @@ services:
     restart: unless-stopped
     networks: [app, data]
     environment:
+      # User / TZ
       USER_UID: "1000"
       USER_GID: "1000"
+      TZ: ${TZ:-Europe/Amsterdam}
+
+      # Server posture — nginx terminates TLS, gitea speaks HTTP on 3000
       GITEA__server__ROOT_URL: ${GITEA_ROOT_URL}
+      GITEA__server__DOMAIN: ${GITEA_DOMAIN:-git.wbd-rd.nl}
+      GITEA__server__PROTOCOL: http
       GITEA__server__DISABLE_SSH: "true"
+      GITEA__server__OFFLINE_MODE: "false"
+
+      # Skip web installer (admin user + OIDC source provisioned via CLI)
+      GITEA__security__INSTALL_LOCK: "true"
+
+      # Database — postgres on sql stack (DB+role auto-provisioned)
       GITEA__database__DB_TYPE: postgres
       GITEA__database__HOST: ${GITEA_DB_HOST:-sql:5432}
       GITEA__database__NAME: ${GITEA_DB_NAME:-gitea}
-      GITEA__database__USER: ${GITEA_DB_USER}
+      GITEA__database__USER: ${GITEA_DB_USER:-gitea}
       GITEA__database__PASSWD: ${GITEA_DB_PASSWORD}
-      TZ: ${TZ:-Europe/Amsterdam}
+
+      # Disable local registration; users come in via Keycloak OIDC
+      GITEA__service__DISABLE_REGISTRATION: "true"
+      GITEA__service__ALLOW_ONLY_EXTERNAL_REGISTRATION: "true"
+      GITEA__service__SHOW_REGISTRATION_BUTTON: "false"
+      GITEA__service__REQUIRE_SIGNIN_VIEW: "true"
+      GITEA__openid__ENABLE_OPENID_SIGNIN: "false"
+      GITEA__openid__ENABLE_OPENID_SIGNUP: "false"
+
+      # OIDC client behavior — auth source itself added via CLI (see README)
+      GITEA__oauth2_client__ENABLE_AUTO_REGISTRATION: "true"
+      GITEA__oauth2_client__UPDATE_AVATAR: "true"
+      GITEA__oauth2_client__USERNAME: nickname
+      GITEA__oauth2_client__ACCOUNT_LINKING: auto
+
+      # Mail (flip ENABLED to true after postfix stack is up)
+      GITEA__mailer__ENABLED: "false"
+      GITEA__mailer__SMTP_ADDR: postfix
+      GITEA__mailer__SMTP_PORT: "25"
+      GITEA__mailer__FROM: ${GITEA_MAIL_FROM:-gitea@wbd-rd.nl}
+
+      # Repo defaults
+      GITEA__repository__DEFAULT_PRIVATE: private
+      GITEA__repository__DEFAULT_PUSH_CREATE_PRIVATE: "true"
+
+      # Exposed inside the container so the OIDC-source CLI command can pick them up
+      # (gitea itself doesn't read these — they're only for the post-deploy CLI step)
+      GITEA_OAUTH_CLIENT_ID: ${GITEA_OAUTH_CLIENT_ID:-gitea}
+      GITEA_OAUTH_CLIENT_SECRET: ${GITEA_OAUTH_CLIENT_SECRET}
+      GITEA_OAUTH_DISCOVERY_URL: ${GITEA_OAUTH_DISCOVERY_URL:-https://auth.wbd-rd.nl/realms/wbd/.well-known/openid-configuration}
+
     volumes:
       - gitea-data:/data