Docker: read every setting from a .env file

Each folder gets a .env.example listing every homeserver, admin panel
and web client setting with its default (empty means the default).
Compose reads .env for ports, registry and the PostgreSQL password, and
passes it to the containers through env_file; the compose files keep
only the database driver, connection string and internal addresses.
.env is git-ignored.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Docker-AIO/docker-compose.sqlite.yml

@@ -2,7 +2,8 @@
 # client in one container, built from this checkout.
 #
 #   cd Docker-AIO
-#   WARP_SERVER_NAME=matrix.example.org docker compose -f docker-compose.sqlite.yml up -d --build
+#   cp .env.example .env      # then edit it
+#   docker compose -f docker-compose.sqlite.yml up -d --build
 #
 # Homeserver http://localhost:8008, admin panel http://localhost:8009, web
 # client http://localhost:8080. The database, signing key and media live
@@ -21,12 +22,9 @@ services:
       dockerfile: Docker-AIO/Dockerfile
     image: warp-aio:latest
     restart: unless-stopped
+    env_file: .env
     environment:
-      WARP_SERVER_NAME: ${WARP_SERVER_NAME:-localhost}
-      WARP_WELL_KNOWN_CLIENT_BASE_URL: ${WARP_PUBLIC_BASEURL:-http://localhost:8008}
       WARP_DB_DRIVER: sqlite
-      WARP_REGISTRATION_ENABLED: ${WARP_REGISTRATION_ENABLED:-false}
-      WARP_FEDERATION_ENABLED: ${WARP_FEDERATION_ENABLED:-false}
     volumes:
       - warp-data:/data
     ports: