Changes in version 0.0.1 (2026-09-21)                  

CRAN resubmission

  - Examples that download data now use \donttest{} instead of
    \dontrun{}, as requested by CRAN.
  - mg_string_species() now returns the documented taxon_id column: the
    leading # of the STRING #taxon_id header is stripped instead of
    being kept in the column name.

Initial release of the mechanism evidence graph data model. Built
demand-driven: the first real consumer is the NSEA workflow
(clusterProfiler::nseGO() / ReactomePA::nsePathway()), which now accepts
a mechgraph network through enrichit::prepare_network().

Core container

  - mg_graph(), mg_empty(), mg_validate(), is_mechgraph(): construct and
    validate a mechgraph object (nodes/edges/metadata base data.frame
    tables).
  - Accessors mg_nodes(), mg_edges(), mg_metadata(), mg_sources().
  - Mutators mg_add_nodes(), mg_add_edges(), mg_drop_nodes(),
    mg_drop_edges(), mg_bind(), mg_combine().
  - Filters mg_filter_nodes(), mg_filter_edges(), mg_induced_subgraph().
  - Builder mg_from_edges(), coercion as_mechgraph().
  - QC summary mg_qc().

STRING backend

  - mg_from_string(): download and map a STRING functional or physical
    network (protein.links / protein.physical.links) into a mechgraph
    with type = "ppi" edges carrying the STRING combined score and full
    provenance metadata.
  - Identifier mapping through the STRING protein.aliases table: keytype
    = "entrez" (default), "symbol", "uniprot", "ensembl_gene",
    "ensembl_protein", "string_id".
  - mg_string_versions(), mg_string_file_url(), mg_string_download()
    (cached), mg_string_parse(), mg_string_species().

BioGRID backend

  - mg_from_biogrid(): download and parse BioGRID multi-validated
    physical interactions (TAB3/MITAB) into a mechgraph with type =
    "ppi" edges.
  - mg_biogrid_versions(), mg_biogrid_file_url(), mg_biogrid_download()
    (cached), mg_biogrid_parse().