Use Starlette, uvicorn and websockets; rename Docker files to container ones

Serve neo4j-browser with Starlette and uvicorn (the optional browser extra)
instead of a hand-written HTTP server, and handle Bolt over WebSocket with the
websockets library's Sans-I/O protocol. Rename Dockerfile, .dockerignore and
docker/ to Containerfile, .containerignore and container/.

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

README.md

@@ -32,9 +32,17 @@ The `binary` extra pulls in psycopg's prebuilt wheels; leave it out to use a psy
 built against your system's libpq. `python -m peo` works the same as `peo`.
 
 Neo4j clients can now connect to `neo4j://localhost:7687` with a PostgreSQL user name
-and password. peo does not include neo4j-browser itself: build it and point
-`PEO_BROWSER_DIR` at its `dist` directory to serve it on <http://localhost:7474/>, or
-use the container image.
+and password.
+
+peo does not include neo4j-browser itself. To serve it, install the `browser` extra
+([Starlette](https://www.starlette.io/) and [uvicorn](https://www.uvicorn.org/)),
+build neo4j-browser and point `PEO_BROWSER_DIR` at its `dist` directory; it is then
+served on <http://localhost:7474/>. The container image does all of this for you.
+
+```sh
+pip install 'peo[binary,browser]'
+PEO_PG_HOST=localhost PEO_PG_DATABASE=postgres PEO_BROWSER_DIR=/path/to/neo4j-browser/dist peo
+```
 
 ## Configuration
 
@@ -48,7 +56,7 @@ peo is configured through environment variables:
 | `PEO_DEFAULT_GRAPH` | `neo4j` | Graph used when a client does not pick a database. |
 | `PEO_BOLT_PORT` | `7687` | Port the Bolt server listens on (TCP and WebSocket). |
 | `PEO_HTTP_PORT` | `7474` | Port neo4j-browser is served on, when `PEO_BROWSER_DIR` is set. |
-| `PEO_BROWSER_DIR` | (unset) | neo4j-browser `dist` directory to serve. |
+| `PEO_BROWSER_DIR` | (unset) | neo4j-browser `dist` directory to serve; needs the `browser` extra. |
 | `PEO_ADVERTISED_BOLT_PORT` | `$PEO_BOLT_PORT` | Bolt port advertised to the browser; set it when clients reach the Bolt port on another port. |
 | `PEO_ADVERTISED_HOST` | `localhost` | Host reported in `SHOW DATABASES` and to clients that do not send a routing address. |
 | `PEO_LOG_LEVEL` | `INFO` | `DEBUG` logs every generated SQL statement. |
@@ -151,7 +159,9 @@ pgAdmin comes with the bundled PostgreSQL server already registered as "peo";
 it asks for the PostgreSQL password the first time you open it. AGE stores each
 graph as a schema of the same name, with one table per label.
 
-`docker` works as a drop-in replacement for `podman` in the commands above.
+Any OCI-compatible build tool works. With Docker, pass the file name explicitly:
+`docker build -f Containerfile -t peo .`; `docker run` takes the same options as
+`podman run`.
 
 Besides peo's own variables above, the image uses these:
 
@@ -186,11 +196,12 @@ This is a first version. Things that do not work (yet):
 
 ## Development
 
-peo's only dependency is `psycopg` 3. To work on it, install it in editable mode;
-`python -m build` (or `uv build`) builds an sdist and wheel:
+peo depends on `psycopg` 3 and `websockets`, plus Starlette and uvicorn for the
+`browser` extra. To work on it, install it in editable mode; `python -m build` (or
+`uv build`) builds an sdist and wheel:
 
 ```sh
-pip install -e '.[binary]'
+pip install -e '.[binary,browser]'
 ```
 
 [`tests/smoke_test.py`](tests/smoke_test.py) runs end-to-end checks through the official