feat(cli): Replace mcp run with click CLI and runtime options

BREAKING CHANGE: FASTMCP_-prefixed env vars have been replaced by CLI
arguments. Refer to the README for updated usage.

Usage: python -m nextcloud_mcp_server.app [OPTIONS]

Options:
  -h, --host TEXT
  -p, --port INTEGER
  -w, --workers INTEGER
  -r, --reload
  --log-level [critical|error|warning|info|debug|trace]
  -t, --transport [sse|streamable-http]
  -e, --enable-app [notes|tables|webdav|calendar|contacts]
                                  Enable specific Nextcloud app APIs. Can be
                                  specified multiple times. If not specified,
                                  all apps are enabled.
  --help                          Show this message and exit.

Dockerfile

@@ -6,4 +6,4 @@ COPY . .
 
 RUN uv sync --locked --no-dev
 
-CMD ["/app/.venv/bin/mcp", "run", "--transport", "sse", "/app/nextcloud_mcp_server/app.py:mcp"]
+ENTRYPOINT ["/app/.venv/bin/python", "-m", "nextcloud_mcp_server.app"]