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>

container/pgadmin/config_distro.py

@@ -0,0 +1,20 @@
+# SPDX-FileCopyrightText: 2026 Bart Broere
+# SPDX-License-Identifier: GPL-3.0-or-later
+# pgAdmin settings for the peo image, loaded via CONFIG_DISTRO_FILE_PATH.
+# Paths derived from DATA_DIR in pgAdmin's config.py are computed before this
+# file is applied, so they are all set explicitly here.
+
+DATA_DIR = '/var/lib/pgadmin'
+SQLITE_PATH = DATA_DIR + '/pgadmin4.db'
+SESSION_DB_PATH = DATA_DIR + '/sessions'
+STORAGE_DIR = DATA_DIR + '/storage'
+KERBEROS_CCACHE_DIR = DATA_DIR + '/krbccache'
+AZURE_CREDENTIAL_CACHE_DIR = DATA_DIR + '/azurecredentialcache'
+LOG_FILE = '/dev/null'
+
+SERVER_MODE = True
+UPGRADE_CHECK_ENABLED = False
+
+# From the config_distro.py shipped in the pgadmin4 wheel, which this replaces.
+HELP_PATH = '../../docs/en_US/_build/html/'
+MINIFY_HTML = False